InCallUI: Disable Back button on Non-intursive InCall Card

Fix for jira issue http://jira.omnirom.org/browse/OMNI-296

PS2 to PS5: code cleanup

PS6: Remove Jira issue url from code

Change-Id: I257daccbb175265e2430f1b0b30c9175cb4b1981
Revert "Optipng -nc -nb -o7"

This reverts commit dd1767513231852599e201842226ef0b651ab33d.
In-Call UI from blue to white

we changed the default dialpad from blue to white
but forgot this in call dialpad,
make it white ui to be consistent

Change-Id: Ie715340d69adb1514e5f1d5bb159b8c42494015a
trds cleanup.

Change-Id: I05f1cfcee4a7048c8c869cc008d291bf5072bb93
Signed-off-by: scott <scott@ubuntu>