Add an xcworkspace
Update README getting started steps
Move RAC dependency to the workspace level

This allows applications to depend on RAC (or other libraries depending on RAC) without conflicts.
No need to link RAC into the DeviceRotation demo

It's included as part of RCL.
Remove auto-added Framework Search Paths
Remove more auto-added search paths
Reference ReactiveCocoa.framework relative to BUILT_PRODUCTS_DIR
Merge pull request #52 from github/workspace

Add an xcworkspace, move RAC reference into it