Settings: Alert user when they attempt to add an invalid number to BL.

  - BlacklistProvider will reject numbers that aren't valid, silently. So instead of
  resuming to a blank screen, we should alert the user that the number they attempted to
  add is invalid by utilizing BlacklistUtils#addOrUpdate method.

Change-Id: I1ca32427baad41c1c9379e18046e6ca7937b6d32
settings: prevent NPE if device doesn't support ActionBar

If the device FEATURE_ACTION_BAR (the device hasn't it enabled or a theme has disabled it), getActionBar()
will return a null reference. Just prevent to use that invalid ref.

JIRA: BUGDUMP-23210
https://jira.cyanogenmod.org/browse/BUGDUMP-23210
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>

Change-Id: I210867b10193471c49e444c27c47e9de6baee822
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Settings into android-4.4