Added underlyingView property to get background content from a view other than superview
Fix spinloop, updates of hidden views

Takes up much less CPU now (sleeps instead of spins when waiting for the next update)
Merge remote-tracking branch 'tleavy86/master'

Conflicts:
	FXBlurView/FXBlurView.m
Always prepare superview before snapshot; Remove superfluous parameters
Merge pull request #31 from Clinkle/master

Add underlying view (With bugfix)
Updated to version 1.5
Merge branch 'master' of https://github.com/nicklockwood/FXBlurView

Conflicts:
	FXBlurView.podspec
	FXBlurView/FXBlurView.h
	FXBlurView/FXBlurView.m
	LICENCE.md
	RELEASE NOTES.md
Updated to version 1.5
Removed duplicated code by extracting things into separate methods
Added missing statement to call completion block in one of the branches
Merge pull request #34 from JaviSoto/master

Fixef DRYness in -updateAsynchronously: method
Updated to version 1.5.1
Merge pull request #1 from nicklockwood/master

Update