Take the internal functions and definitions back out of the implementation
namespace:

:g/\<__ops/s//pgp/g
:g/\<__OPS/s//__PGP/g
:g/\<OPS/s//PGP/g

No functional change, regression tests complete successfully.

CHANGES 1.99.3 -> 1.99.4

+ get rid of some magic constants
+ revamped regression test script to count number of tests passed
+ made checkhash array in ops_seckey_t dynamic, rather than statically
allocated
+ made mdc array dynamic, and added a length field to mdc for future use
+ revamped usage message to match reality
+ made portable version again for the autoconfed package sources
+ add separate netpgpdigest.h file so that separate digest sizes can be
used without having to include "packet.h" in everything