Make MKParallaxView Storyboard friendly

* move init code from initWithFrame to individual method initCommon and
call it from initWithFrame and awakeFramNib
Add gitignore to ignore Xcode user data files
Merge pull request #3 from kinwo/master

Make MKParallaxView Storyboard friendly
Merge Conflicts Meant I needed to merge augard's changes in manually
Update README.md
Added Clips to Bounds YES to the view controller (just in case)
Merge remote-tracking branch 'upstream/master'

Conflicts:
	MKParallaxView/MKParallaxView.m