Update documentation of git_oid_streq to remove outdated error code
oid: git_oid_shorten_add() sets GITERR_INVALID when OID set is full
Merge pull request #1819 from linquize/git_oid_shorten_add

oid: git_oid_shorten_add() sets GITERR_INVALID when OID set is full
Merge pull request #1820 from linquize/git_oid_streq

Update documentation of git_oid_streq to remove outdated error code
Removing unneeded code duplication in ls-remote.c
Adding credentials callback to ls-remote and fetch too.
Build all example files if BUILD_EXAMPLES used.
Merge pull request #1822 from kadamski/examples-cleanup

Small cleanup in examples.