Added support for mutliple audio streams.

ShadowAudioManager can now track individual stream status. Removed global
streamMaxVolume, streamVolume and flags, as they are replace with
streamStatus. Removed methods getStreamVolume(), getStreamMaxVolume() and
getFlags().

Closes #915, #907.
Add ShadowWindow#getSoftInputMode
Fixes NullPointerException when using @Config manifest NONE.

Closes #913.
Add non-Android accessor for OnSystemUiVisibilityChangeListener.
basic support for GradientDrawable#getColor()
Merge pull request #923 from pivotal-odell/systemUiVisibilityChangeListener

Add non-Android accessor for OnSystemUiVisibilityChangeListener.
Can setHasPermanentMenuKey on ViewConfiguration
Merge pull request #922 from pivotal-odell/gradientDrawable-getColor

Basic support for GradientDrawable#getColor()
Merge pull request #924 from pivotal-odell/viewConfiguration-setHasPermamentMenuKey

Can setHasPermanentMenuKey on ViewConfiguration