include strings.h where appriopriate...

instead or additionally to string.h, in preparation for functions move.
* moves str[n]casecmp() functions and others to strings.h.
* strings.h doesn't include string.h anymore.
* this solves #10949

Move {en,de}code_base64 to the support kit

It's not possible to use these from the network kit otherwise, as it
would create a circular dependency (mail > bnetapi > mail).

Is there a better way to solve this problem?

Made mail_encoding a proper C++ file.

* This unbreaks the GCC2 build, thanks Matt!

include strings.h where appriopriate...

instead or additionally to string.h, in preparation for functions move.
* moves str[n]casecmp() functions and others to strings.h.
* strings.h doesn't include string.h anymore.
* this solves #10949

Move {en,de}code_base64 to the support kit

It's not possible to use these from the network kit otherwise, as it
would create a circular dependency (mail > bnetapi > mail).

Is there a better way to solve this problem?

Made mail_encoding a proper C++ file.

* This unbreaks the GCC2 build, thanks Matt!