Fix src frame buffer copy and extend

For input source with size that is not multiple of 8, the size is
rounded to 8 and saved in width or height, the original source sizes
are saved in crop_width and crop_height. This commit corrects the
computation of bottom and right extension amounts to use the orignal
sizes, hence crop_width and crop_height.

In addition, this commit also adds the missed initialization for
uv_crop_width and uv_crop_height.

This addresses issue #834

Change-Id: I084543ca7645a4964b88f7cf8ff668f517d3a39b
vp8: Suppress denoising with respect to old reference frames.

If the GOLDEN or ALTREF frame was last updated > x frames in the past,
don't use them for denoising (only consider LAST). Using an old reference
frame for denoising, e.g., if it is a long-term reference or the last key frame,
can cause some visible artifacts, in particular in the aggressive denoising mode.

Change-Id: I239c9fbb092c36cba7e95328f1fa67a58d6a7ed9
Merge "Fix src frame buffer copy and extend"
Merge "vp8: Suppress denoising with respect to old reference frames."