Log Message:
Update tinycdb to 0.77.

pkgsrc changes:
* simplify subst with SUBST_VARS.
* build and install shared library.
* install pkgconfig file.

package changes:

tinycdb-0.77

 - bugfix release: manpage typos, portability fixes and the like

 - bugfix: improper logic in EINTR handling in _cdb_make_full_write
   routine which may lead to corruped .cdb file.