Parse a revision string for from
, to
, and intent.
See man gitrevisions
or
http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions for
information on the syntax accepted.
Pointer to an user-allocated git_revspec struct where the result of the rev-parse will be stored
the rev-parse spec to parse
0 on success, GIT_INVALIDSPEC, GIT_ENOTFOUND, GIT_EAMBIGUOUS or an error code