Allow disabling of automatic screen blanking from lock screen

New config setting "/system/osso/dsm/locks/tklock_blank_disable".

When enabled, tklock module uses longer timeouts for display
dimming / blanking. Effectively the lock screen is shown until
power key is pressed.

The config setting can be toggled with:
  mcetool --set-tklock-noblank=enabled|disabled
Setting tklock_blank_disable blocks automatic display dim/blank forever

The fake dim/blank timeouts now - in addition to using longer than normal
delays - repeat without performing the dim/blank action.
Merge pull request #34 from spiiroin/do_not_blank_lockscreen

Allow disabling of automatic screen blanking from lock screen