A few initial tests for commit parsing:

    "parse_buffer_test" tests git_commit__parse_buffer() with
    several malformed commit messages and a few corner cases
    which should pass.

    "parse_oid_test" tests git_commit__parse_oid() with several
    malformed commit lines containing broken SHA1 OIDs.

Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Andreas Ericsson <ae@op5.se>