Try a prefix header for importing libgit2's git2.h
Import more focused libgit2 headers where possible
Revert "Try a prefix header for importing libgit2's git2.h"

This reverts commit 7808a8ff7ffb4fd61e8b5b0a9a9c86eb3ec4a52d.
Update objc-build-scripts to stop cleaning automatically
Add missing libgit2 header imports
Revert "Add missing libgit2 header imports"

This reverts commit 6640f904e1786642a8a6c1c3a0fde8dacae450ba.
Revert "Import more focused libgit2 headers where possible"

This reverts commit 2c0885e4754bf0657183f958d856f3d0a198d87d.
Revert 6640f90..9b9af54

This rolls back to commit 6640f904e1786642a8a6c1c3a0fde8dacae450ba.
Merge pull request #417 from libgit2/optimize-build

Use more granular libgit2 imports, don't clean every build