remove whitespace at EOL from code extracted from SUPERCOP

Update the sntrup761 creation script and generated code:
- remove unneeded header files and typedefs and rely on crypto_api.h
- add defines to map types used to the crypto_api ones instead of typedefs. This
prevents typedef name collisions in -portable.
- remove CRYPTO_NAMESPACE entirely instead of making it a no-op
- delete unused functions and make the remaining ones that aren't exported static.

ok djm@

estructure sntrup761.sh to process all files in a single list, which will
make it easier to reorder. Re-inline int32_MINMAX. ok tobhe@

Prevent redefinition of `crypto_int32' error with gcc3.
Fixes compilation on luna88k.

Feedback millert@
Found by and ok aoyama@

Use int64_t for intermediate values in int32_MINMAX to prevent signed
32-bit integer overflow.

Found by and ok djm@
ok markus@

Update/replace the experimental post-quantim hybrid key exchange
method based on Streamlined NTRU Prime (coupled with X25519).

The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.

The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).

Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself

(note this both the updated method and the one that it replaced are
disabled by default)

Update the sntrup761 creation script and generated code:
- remove unneeded header files and typedefs and rely on crypto_api.h
- add defines to map types used to the crypto_api ones instead of typedefs. This
prevents typedef name collisions in -portable.
- remove CRYPTO_NAMESPACE entirely instead of making it a no-op
- delete unused functions and make the remaining ones that aren't exported static.

ok djm@

estructure sntrup761.sh to process all files in a single list, which will
make it easier to reorder. Re-inline int32_MINMAX. ok tobhe@

Prevent redefinition of `crypto_int32' error with gcc3.
Fixes compilation on luna88k.

Feedback millert@
Found by and ok aoyama@

Use int64_t for intermediate values in int32_MINMAX to prevent signed
32-bit integer overflow.

Found by and ok djm@
ok markus@

Update/replace the experimental post-quantim hybrid key exchange
method based on Streamlined NTRU Prime (coupled with X25519).

The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.

The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).

Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself

(note this both the updated method and the one that it replaced are
disabled by default)

estructure sntrup761.sh to process all files in a single list, which will
make it easier to reorder. Re-inline int32_MINMAX. ok tobhe@

Prevent redefinition of `crypto_int32' error with gcc3.
Fixes compilation on luna88k.

Feedback millert@
Found by and ok aoyama@

Use int64_t for intermediate values in int32_MINMAX to prevent signed
32-bit integer overflow.

Found by and ok djm@
ok markus@

Update/replace the experimental post-quantim hybrid key exchange
method based on Streamlined NTRU Prime (coupled with X25519).

The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.

The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).

Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself

(note this both the updated method and the one that it replaced are
disabled by default)

Prevent redefinition of `crypto_int32' error with gcc3.
Fixes compilation on luna88k.

Feedback millert@
Found by and ok aoyama@

Use int64_t for intermediate values in int32_MINMAX to prevent signed
32-bit integer overflow.

Found by and ok djm@
ok markus@

Update/replace the experimental post-quantim hybrid key exchange
method based on Streamlined NTRU Prime (coupled with X25519).

The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.

The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).

Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself

(note this both the updated method and the one that it replaced are
disabled by default)

Use int64_t for intermediate values in int32_MINMAX to prevent signed
32-bit integer overflow.

Found by and ok djm@
ok markus@

Update/replace the experimental post-quantim hybrid key exchange
method based on Streamlined NTRU Prime (coupled with X25519).

The previous sntrup4591761x25519-sha512@tinyssh.org method is
replaced with sntrup761x25519-sha512@openssh.com. Per the authors,
sntrup4591761 was replaced almost two years ago by sntrup761.

The sntrup761 implementaion, like sntrup4591761 before it, is public
domain code extracted from the SUPERCOP cryptography benchmark
suite (https://bench.cr.yp.to/supercop.html).

Thanks for Daniel J Bernstein for guidance on algorithm selection.
Patch from Tobias Heider; feedback & ok markus@ and myself

(note this both the updated method and the one that it replaced are
disabled by default)