Check and fail early if requested wallpaper size exceeds maximum texture size.

This fixes an issue where OpenGL initialization succeeds but buffer allocation fails because the requested wallpaper size
is too large (or otherwise unsupported) by the graphics hardware. This fixes an issue where SystemUI crashes constantly
on the PandaBoard when connected to a full HD display. Tested only on PandaBoard, no access to alternative hardware.
Signed-off-by: Wim Vander Schelden <wim.vander.schelden@philips.com>

Change-Id: I8d2e1ae9fd9772977c4e365f23f2f58bbca3787c
Performance increase in thumbnail handling

Allow for 160*120 thumbnails which is what cameras commonly
generates. The constants for the micro thumbnail were set to other
values, resulting in recalculations of the thumbnais, which
takes time.

This change only affects the maximum size of the temporary image,
when choosing whether to use the EXIF thumbnail or decoding and
downsampling the full image. Without this change, it will choose
an x16 downsampling of the full image over an x2 downsampling of
the EXIF thumbnail, after the change it will prefer the EXIF
thumbnail.

Cf the DCF specifications at http://www.exif.org/dcf.PDF,
"3.3.6. DCF basic thumbnail data structure, (C) Pixel count"

Tested by running DDMS and measuring the time required to create
a thumbnail. This was 220-280 ms prior to change, < 20 ms after.

Change-Id: I59c753493f947e920bad3fde5eeed5d49d509863
Merge changes I59c75349,I8d2e1ae9 into jb4.2

* changes:
  Performance increase in thumbnail handling
  Check and fail early if requested wallpaper size exceeds maximum texture size.