* common/stringhelp.c: Include limits.h.
(compare_version_strings): Change semantics to behave like strcmp.
Include the patch lebel in the comparison. Allow checking a single
version string.
* common/t-stringhelp.c (test_compare_version_strings): Adjust test
vectors and a few new vectors.
* g10/call-agent.c (warn_version_mismatch): Adjust to new sematics.
* g10/call-dirmngr.c (warn_version_mismatch): Ditto.
* sm/call-agent.c (warn_version_mismatch): Ditto.
* sm/call-dirmngr.c (warn_version_mismatch): Ditto.
Signed-off-by: Werner Koch <wk@gnupg.org>