Adding highlighted images support for allert views
Adding highlighted images support for action sheets
Merge pull request #48 from brunokoga/master

Adding support for different images for the UIControlStateHighlighted state
alert: added addButtonWithTitle:imageIdentifier:block: to allow for using any alert image of the form "alert-IDENTIFIER-button.png"
added green alert button and updated demo project to use it
updated podspec
Merge remote-tracking branch 'upstream/master' into upstream

Conflicts:
	BlockAlertsDemo.xcodeproj/project.pbxproj
	BlockAlertsDemo/ToAddToYourProjects/BlockAlertView.m