Xcode6 support with releasable framework, Remove support for Xcode5

This adds proper XCode6 support. There is a new configuration Release-Combined which is built from build.sh (and can be built from xcode). This configuration builds and tests a fat framework and installs it at build/ios/Realm.framework

All examples have been updated to work with the new framework.

@tgoyne @jpsim 
need to fix all these paths