integrate libgit2 read tree function
tree5d68bcf6ebd4e7a20f5a4c28db46f0ec0e30114f
-rw-r--r-- 596 .gitignore
-rw-r--r-- 495 .gitmodules
drwxr-xr-x - Languages
-rw-r--r-- 3438 build.txt
drwxr-xr-x - common
drwxr-xr-x - contrib
drwxr-xr-x - doc
drwxr-xr-x - ext
drwxr-xr-x - src
drwxr-xr-x - test