upgraded libgit2 to version 0.17.0
treeafc42339b608cde6b2e3d34fdca0c307f370e72f
-rw-r--r-- 367 .gitignore
-rw-r--r-- 543 .gitmodules
drwxr-xr-x - Languages
-rw-r--r-- 3425 build.txt
drwxr-xr-x - common
drwxr-xr-x - contrib
drwxr-xr-x - doc
drwxr-xr-x - ext
-rw-r--r-- 145 release.txt
drwxr-xr-x - src
drwxr-xr-x - test