Updated version for next release 0.0.6
Handle elevation on API 21 devices

It's not overly clean, feel free to rework it if necessary, but I managed to get a shadow similar to Google apps.
Use only the circle to draw the shadow on API 21
Bump target sdk version
Extracted circle-drawable to separated xml; implicitly set up elevation (allow to disable this property in order to use custom value); optimized loading of drawable for API 21.
Merge branch 'master' into release

Conflicts:
	gradle.properties