Add Flash-Friendly File System (f2fs) support.

Change-Id: If46bf7329a7453122a4379f9bc41cf9553426e74
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_system_vold into temp
Revert all changes

Change-Id: I1908865d249c77d2ce780d866b6ac848e8b14d3e