Allow purging of asset bitmaps

It seems that neither CM9 nor CM10.x includes the actual framework-side
code to facilitate user-controllable bitmap purging. Odd, since the
CyanogenMod Settings app in both CM9/CM10.x includes the option.

Backported from original Gingerbread commit:
http://review.cyanogenmod.org/#/c/3908

Original description:

Allow the system to reclaim more free RAM when needed on 'low' memory devices
(e.g. Droid/Milestone) that are struggling with 2.3. This option enabled
efectively restores the froyo way of forcePurgeable BitmapFactory asset
handling.

Change-Id: I6a3b8a05b7be9c214a8548d6c6d1621e6533a1e0
Patch Set 1/2: Add an "Automatically Connect" option for WiFi networks

Allows the ability for a user to determine whether to connect to an SSID automatically.
e.g. At work, there are several SSIDs with long, complex keys.
    I don't want to connect to them all of the time, but would like them to be remebered.
The default behaviour is to allow automatic connection, as it is today.

Change-Id: If6fb33d5aff91688aec73317a9e43c9e210f90fc