Settings: Day and week on data usage cycle (2/2)

Adds the ability to set day and week on when the data usage graph resets, instead of just month.

Change-Id: I5974e1b7143d09ffd6fcd6db113c3f7511346bfa
Merge "Settings: Day and week on data usage cycle (2/2)" into cm-11.0
Merge pull request #15 from CyanogenMod/cm-11.0

sync fork