Add a class for display gamma control

Same basic concept as kcal, but it accepts and manages multiple RGB triplets

Change-Id: I8fffc94b439a366a5aa38277ae971ab3aaa3589b
Hardware: Add AdaptiveBacklight support

Patchset 2: Fix javadoc
Patchset 3: Rename to AdaptiveBacklight
Patchset 4: Fix typo in javadoc comment

Change-Id: I50190833da67d7f574d42d48a52eb5c610b4966e
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
Merge "Hardware: Add AdaptiveBacklight support" into cm-10.2
Merge branch 'cm-10.2' into martincz