Changed --output-shift option

--output-shift now infers the amount to shift
from the bitdepth of the decoded file.

Option has been renamed to
--convert-to-8bit

Change-Id: Ieb2945bb282bb81c52a0c4f1b691c82bec5ec18c
Added rounding when using --output-shift

PSNR values are slightly improved by using
rounding when shifting images back to 8bit.

Change-Id: Ida70ca48588f933a92f906cd1ebc8e88134c07f5
Fixed --test-decode for high bitdepth

Change-Id: I02b72dafad80a22ff0546a64c4a0fe757ac66861
Fixed temporal filter rounding

The temporal filter goes wrong
when strength is equal to 0.

See Issue 787.

Change-Id: I983c5983c34359ca78743a2434fb536c3a9b3e72
Merge "Fixed temporal filter rounding" into highbitdepth
Merge changes Ida70ca48,Ieb2945bb into highbitdepth

* changes:
  Added rounding when using --output-shift
  Changed --output-shift option
Deprecates --input-shift parameter

Deprecates --input-shift parameter and instead derives that from
bit-depth assuming 8-bit input source. Eventually this needs to be
derived from the input-bit-depth parameter once we support high
bit depth input. Another parameter --test-high-internal is added
to force use of 16 bit internal buffers for testing purposes, in
profile 0 and 1.

Also --bit-depth parameter now uses values 8/10/12 which is more
intuitive than 0/1/2.

Also includes some cleanups.

Change-Id: I0bdd6d9caae8bb339d217551bb35a001057805ec