Bring Mozilla ESR17 branch to the 17.0.11 level

This commit merges the changes that Bitwise has done for the OS/2 port with the changes between FF17.0.5 and FF17.0.11 along with aligning with my personal tree.
Reenable the Contacts API on ESR 17

Not sure why this was disabled as I can't read the bug but it makes building SeaMonkey and Thunderbird easier