Backport "Add Blacklist functionality" from CM10.1 (Part1)
Part 1 is only the blacklist without incall blocking and notifications

Forward port the Blacklist functionality from CM7.

Original code written by Cytown, modified by Cyanogen (2011-01-04),
nhnt11 (2011-05-24) and maniac103 (2012-10-02).

Originally forwardport for CM10.1 by: DvTonder
Backported from CM10.1 by: Daveee10