Merge pull request #1762 from mobiware/background-android3

Implementing mobile:background command for Android and Selendroid
Added doc for nativeInstrumentsLib cap
Merge pull request #1764 from sebv/extra-caps

Added doc for nativeInstrumentsLib cap
use a messy loop instead of a deeply nested async fn chain (fix #1523)
Merge pull request #1765 from jlipps/fix-max-stack

fix max call stack in keytool zip issue