- Add ~dispasstest~ which is used to test the DisPass algorithms.
- Remove =main= from libdispass since shared libraries shouldn't have
main functions
- Add ~dispass.h~ which defines and exports the DisPass algorithms.
- Make some functions in ~dispass.c~ static to make clear they're not
exported anywhere.
- Remove some unused variables
- Explicitly cast =tbuff= to a pointer to =unsigned char= when using
=SHA512=.
- Use =long long unsigned= as =seqno=, since there is no theoretical
limit to it.
- Use =size_t= for the =tbufflen= variable in =dispass1= since
technically that is what =strlen= returns.