CB-6986 make npm run jshint work without a global jshint

Add jshint to dev-deps in package.json and use it instead of relying on a
global jshint.

github: close #37
CB-3571: support for <splash> element in config.xml on Android
change indentation from 2 to 4 spaces
Adds support for splashscreens to wp8, windows8 and ios platforms
Refactor and cleanup android implementation:
* Add getSplashScreens method to ConfigParser
* Move common splashscreens/icons logic to getStaticResources method
* Move findByDensity method to ConfigParser
* fix indentation issues
* fix lint errors (+1 squashed commits)