aapt: set interlace handling for png_read_update_info

When png_read_update_info is called, interlace handling
should already be set. This is the recommended usage even
on > libpng 1.5.1 which also takes into account if the
image is interlaced.
improve rotation handling

this commit was rewritten/inspired by one made to our jb 4.1 branch by sonicxml.

cheers buddy!

Change-Id: Ib3b46aa54e7bf6602f8c0557ed770624063af529
ZygoteInit: increase GC threshold amount when preloading to postpone GC

todo: instead of hardcoding this number.. make it dependent on the amount
set for heapgrowthlimit in the build.prop. for now we'll just turn it "off".

Change-Id: I7a6e195b82ebe2f4bd5bbb506e19200d452fa3e5
allow customized memory cache size for webkit

ps2: add missing ;

Change-Id: I3cb12a5026b5f7f78fde1f2368e25e96ef02bf37
todo: test and set this in vendor make files when an optimized amount is found