Add SWIFT_OPTIMIZATION_LEVEL defaults
Add iOS-Framework configuration

And moved the previous Mac-Framework settings up into a new base
configuration file.
Frameworks should define modules by default
Enable module imports by default
Warn when objc_msgSend is used without a cast
Remove TEST_AFTER_BUILD, which is obsolete
Pass -D DEBUG to Swift builds in Debug config

Useful for conditional compilation with #if DEBUG.
Migrate LD_RUNPATH_SEARCH_PATHS to Application

This is needed for iOS too, now that it has frameworks.

Also added `executable_path` to the list, per Xcode’s default setting.
Re-sort Common.xcconfig
Fix up build architecture lists
Merge pull request #27 from jspahrsummers/swift-updates

Swift and Xcode 6 updates