Fixes mapbox/mapbox-ios-sdk/#337
Added call to [super updateConstraints] when no view controller could be found

The early return from the updateConstraints override when the map view isn't contained in a view controller (e.g. if it's embedded in a UIWindow) meant that the super class implementation wasn't being called (as per Apple's documentation: https://developer.apple.com/library/ios/documentation/uikit/reference/uiview_class/UIView/UIView.html#jumpTo_121), causing a crash.
Merge pull request #373 from markbeaton/patch-1

Added call to [super updateConstraints] when no view controller could be found
update copyright
be clearer about iOS 7 support
fixes #359: add contribution guidelines
fixes #382: add log line when using watermarked maps
refs #331: disable user tracking when selecting an annotation
Merge branch 'release' into develop
fixes #391: remove debug flags which make debugging difficult
fix taking out logo bug per @mrzoidberg
refs #350: properly update constraints for logo & attribution
refs #260: fix up attribution button toggling
refs #264: don't try to add nil annotations
fixes #338: properly VACUUM after flushing cache
Add asynchronous means of mapbox source creation.