Replace blurring and darkening code with much better performing sample code

Uses the UIImage+ImageEffects category provided by Apple during WWDC 2013. The sample code can be downloaded here: https://developer.apple.com/downloads/download.action?path=wwdc_2013/wwdc_2013_sample_code/ios_uiimageeffects.zip
Thanks to @ashtom for finding it.
Replace blurring and darkening code with much better performing sample code

Uses the UIImage+ImageEffects category provided by Apple during WWDC 2013. The sample code can be downloaded here: https://developer.apple.com/downloads/download.action?path=wwdc_2013/wwdc_2013_sample_code/ios_uiimageeffects.zip
Thanks to @ashtom for finding it.
Merge pull request #2 from lumaxis/master

Replace blurring and darkening code with much better performing version