Fixed picture of the day resolution issue

The pic of the day thumbnail now is requested so it matches the screen height if it's a wide image or the screen's width if it's a tall image. Looks much nicer! Also refactored a bit adding code which can extract image metadata.
Fixed url encoding issue
Added pan recognizer to image of the day

Properly detects which way the image of the day can pan given that either its width or height is going to match the device's.
Merge branch 'featuredImage' into everything

Conflicts:
	Commons-iOS/LoginViewController.m