Remove dead code.

This hasn't been used since at least 2011, and we're no longer
shipping the data supporting it either.

Change-Id: Ibe42057650b49794c65d6f0d54ed7a492f3b594b
Rework thumbnail handling

Since ids of media file are usually not continuous, the original file of thumbnail are
sparse. When there are big numbers files on ex\
ternal storage, the size of this file will be horrible.
Ex, when the id is 20000, then the .thumbnails/.thumbdata3-xx file will be 50000*10k = 488.28M.
Can refer http://stackoverflow.com/questions/12396715/android-huge-thumbdata4-file-in-dcim-folder
Because after 4.0, MediaProvider will scan any files, this will be a big problem. So I modify MiniThumbFile.java to avoid this.
According to the id, we now produce an index file. In this index file, one id will use BYTES_PER_MINTHUMB_INDEX(8) bytes in offset (i\
d+1)*BYTES_PER_MINTHUMB_INDEX. The data of these 8 bytes is the index of thumbnail file. The first BYTES_PER_MINTHUMB_INDEX bytes kee\
p next available index. And when you need insert a thumbnail, the index increase by 1. In this way, the block data in thumbnail file \
will be continuous. And thus unnecessary zero paddings will not be saved.

Change-Id: I66005dd69b0a5c8f4353bd7a8225d163a654fd2d
Signed-off-by: DHOMD <DHO@dho.im>
Hopefully fix media scanner issues

Please see http://forum.xda-developers.com/showpost.php?p=44370296&postcount=357
For inspiration

Change-Id: I71573992c565e9f32b2256f8ef017cc8ac49b285
Lower the RAM requirement for hardware acceleration

There are legacy devices with about 365 MBytes of RAM
available to the kernel (HDPI with 512 MB RAM onboard).
Lowering the requirement value for available RAM allows
these devices to also use hardware acceleration, thus
making the UI a lot more responsive and fixing bugs like
this: https://dl.dropboxusercontent.com/u/16268774/Screenshots/Phone/Screenshot_2013-10-07-01-27-45.png
(notice the "shadow" is missing)

Change-Id: I1657ee2e52563c4e6c381a8ebb6c102a4c193918
Status bar Auto-Hide

Credit and Thanks to mnm9994u

Change-Id: Ie101c3203617ee1278d3bd601da3ff84a980bb86