vold: Allow specifying the filesystem type when formatting

 * Optional parameter added to "volume format" to specify the filesystem
   type to use. If not specified, default is to auto-detect.
 * Add support for formatting NTFS.
 * Use mke2fs to format when not creating containers.

Change-Id: I2bc0f92d59adb9604b35a1f70febccfba68715d3

Conflicts:
	Ntfs.cpp
	Volume.cpp

	modified:   CommandListener.cpp
	modified:   Ext4.cpp
	modified:   Ntfs.cpp
	modified:   Ntfs.h
	modified:   Volume.cpp
	modified:   Volume.h
	modified:   VolumeManager.cpp
	modified:   VolumeManager.h
	modified:   Ntfs.cpp
	modified:   Volume.cpp

Change-Id: I64707ab72515f970dc78fa4cf2189b3c00ffc747