Hot/dead/other-use pixel removal

[Andrew Baldwin]

Hot or dead pixels occur on all cameras 60D ML builds suffer a few random dead pixels all the time 650D and probably newer cameras have other use focusing pixels appearing at fixed places.

We should attempt to identify and mask these pixels at decode time, or accept a global config file with their positions identified.

[Andrew Baldwin]

Simple dead pixel masking (using same bayer colour pixel from left) added to bitunpacking loop by 1d7954ee36e1bd70b6bda3a1ac012405e335d4ce

[Andrew Baldwin]

Implemented in 1.1.6. Could still be improved though.