Speedup image channel operation + alpha masking + etc

Speedup image channel operation + alpha masking + etc

Refactoring image channel selection algorithm.
Previous version run some unneccessary iterations
to select the offset of channel.
This patch change that we use offset pre-calculated table.
Now we can select & apply O(1) time complexity.
+
Remove unneccessary float operation during alpha masking.
+
Add some more dark magics on linear interpolation jobs.
+
Add some more dark magics on scanline.
Before patch reduced only each-line. This patch also reduce between-line operation
This patch, we can calculate 8 components in one operation.

Change-Id: I3b1ce7abbd5d719cd580c789167970e9012e3dbd
Signed-off-by: Eunki, Hong <eunkiki.hong@samsung.com>