Disable use of mask image for android < 4.4

The use of mask images and animations caused
older android devices to only display rectangles
instead of the actual shape. By switching to the
emulation implementation we avoid this.

fixes #160
Updated position of searchbox symbol and height.

Fixes #172
Fix Spinner position in PullPanel on iOS theme.

Fixes #171
Merge pull request #161 from dankurka/fix_android_buttons

Disable use of mask image for android < 4.4
Merge pull request #173 from kfa/searchbox_ios_styling

Updated position of searchbox symbol and height.
Merge pull request #174 from dankurka/fix_pull_panel

Fix Spinner position in PullPanel on iOS theme.