Merge pull request #10 from yassirh/master

Preventing screen from sleeping
Updated to plugin library 1.0.8 - this includes fixes for Android L compatibility (specifically converting implicit service intents to explicit resolved ones).
Re-ordered menu to put keep screen on option at the top
Incremented version for release
Fixed CPU usage calculations. Previously it was just calculating based
on the current values in /proc/stat. This was incorrect as those
counters are since-boot values. Corrected now by comparing the values to
the previous check and working from the delta instead.

Fixes issue #11
Removed unused import