Added Android L style status bar icons

Added drawables for the new Android L solid style for wifi and 3g. The
new images have a “_l” suffix.
Removed boolean dependency

Made a method to check the mApiLevel and returns true if the API level
is above 20
Merge pull request #15 from matthewcmckenna/master

Added Android L style status bar icons
reused isAndroidL function in getFont method
moved super calls for onPause/onDestroy to end of methods
distinguish between android L developer preview and pre-release versions so users are able to take L screenshots with or without the new icons until they're confirmed
corrected icon for wifi xxhdpi, fixes #17
remove unused string
version to 1.0.6
Updated xxhdpi Wifi icon
Merge pull request #19 from matthewcmckenna/master

Updated xxhdpi Wifi icon