various improvements from MapBox 0.5.0 release

[incanus]

Here's our combined commit from a recent release to bring relevant generally-useful functionality up to date.

As always, feel free to let me know if you don't want any of this and I can adjust the pull request as necessary. In particular, the project reorganization stuff might not be appealing, but personally I like it better and it helps separate use of the code from in-depth development on it, which is nice for users in the former category.

Also per usual, I haven't updated the sample projects as we don't keep these in our version, but nothing drastic should have broken.

• Added support for MapKit-like annotation callouts. (mapbox/mapbox-ios-sdk#23)
• Added methods and a delegate to RMTileCache for proactive background downloading of map tiles.
• Added support for Bézier curves in RMShape. (mapbox/mapbox-ios-sdk#148)
• Improved shape hit testing based on fill rule. (mapbox/mapbox-ios-sdk#166)
• RMShape now automatically sets its annotation's coordinate and projectedBoundingBox after drawing updates. (mapbox/mapbox-ios-sdk#109)
• Adjusted closePath method in RMShape to more reliably close the path.
• Sublayer bug fix. (mapbox/mapbox-ios-sdk#113)
• Allow all types of annotation layers to receive touch events. (mapbox/mapbox-ios-sdk#129)
• Added annotation enabled property to enable/disable touch events. (mapbox/mapbox-ios-sdk#141)
• Moved to resources bundle for assets like images. (mapbox/mapbox-ios-sdk#119)
• Cleanup of project structure & resources for clarity.
• Removed armv6 build architecture.
• Added Interface Builder support for RMUserTrackingBarButtonItem. (mapbox/mapbox-ios-sdk#106)
• Fixed a bug related to user location authorization status changes. (mapbox/mapbox-ios-sdk#101)
• Fixed some pointer initializations.
• Moved from alloc/init combo to new per new conventions.
• Added tile cache capacity getters.
• New method to set zoom level with animation. (mapbox/mapbox-ios-sdk#46)
• New method to set both zoom/center at same time, optionally animated. (mapbox/mapbox-ios-sdk#46)
• Removed RMPath since it's long been replaced by RMShape.
• Added ability to customize user location annotation layer like MapKit. (mapbox/mapbox-ios-sdk#133)
• Fixed bug with zoom level setter not registering user events.
• Allow attempted duplicate adding of annotations without actually duplicating them like MapKit does. (mapbox/mapbox-ios-sdk#169)
• Fixed bug with user halo animations when in compass tracking mode.
• Properly set marker contentsScale based on supplied image.
• Removed extraneous method logging.
• Fixed bug with layoutSubviews related to constraints-based layout. (mapbox/mapbox-ios-sdk#142)
• Improved inline documentation.
• Minor code consistency tweaks.

[trasch]

Thanks a lot for all those improvements! I have just merged the patch and will release it in the next few days, after I have tested the changes.