Reintroduce BOARD_VOLD_EMMC_SHARES_DEV_MAJOR

Code taken from CM7's vold
vold: add ro.vold.umsdirtyratio property

This allows control of what /proc/sys/vm/dirty_ratio is used when USB mounting.
Some platforms like the HTC Desire (bravo) get a _HUGE_ performance boost when
writing to the sdcard when USB mounting if this is set to 20 (which is the default)
on the HTC Desire.

This addresses this issue: http://code.google.com/p/cyanogenmod/issues/detail?id=2949

Basicly it makes it possible to undo or control the effect of this commit:
https://github.com/CyanogenMod/android_system_vold/commit/a28056b38275003895ff5d9576681aca01544822

Change-Id: I86b7bbd02695fb0c19f39448714a219257bf806f
DirectVolume: handle discs with multiple major numbers

CFlag: BOARD_VOLD_DISC_HAS_MULTIPLE_MAJORS

Allows Direct Volume to handle discs with multiple major numbers.
Needed on Samsung Galaxy S II and variants.

For example:
mmcblk0p1 - 179:0
mmcblk0p2 - 179:1
mmcblk0p3 - 179:2
mmcblk0p4 - 256:0
mmcblk0p5 - 256:1

Change-Id: I633ac882a721cde25f0df779b4028efa6be15750
vold: fix an offset one bug that makes partition 4 unusable

Change-Id: Ic8e18e6191ad7ee33162e36060b57a6802cf0883
vold: Add ntfs (read-only) support.

See http://review.cyanogenmod.com/#change,7457 for more info.

Change-Id: Ic841e73be6435e8bbbb22984cc749e27c46826e8
vold: fix handling of discs with multiple majors on DirectVolume::getShareDevice()

The method DirectVolume::getShareDevice() returns an invalid device if the partition referenced by
mPartIdx is bad. A bad partition is one where the major/minor numbers on disk don't match what is
expected.

The original major number is stored for bad partitions so the fix attempts to retrieve it and
return it if applicable.

This fix is one part of fixing ICS encryption on the i777 (and possibly other devices) where bad
partitions may exist.

Change-Id: Ic3b05dbf45315bde502c151f53928ca1891483f0