Bump libgit2.
Merge pull request #29 from xutao/pygit2:fix

Bump libgit2.
Fix memory leak.
Merge pull request #30 from xutao/pygit2:fix

Fix memory leak.
Fix memory leak.
Merge pull request #31 from xutao/pygit2:fix

Fix memory leak.
Drop git_patch_to_str.
Merge pull request #32 from xutao/pygit2:fix

Drop git_patch_to_str.
test
submodule
Merge pull request #34 from huanghuang/pygit2:drop_str

bump libgit2
Merge remote-tracking branch 'origin/master' into gh_douban

Conflicts:
	.gitmodules