Remove RunUnitTests scripts

Not supported in Xcode 5's `xcodebuild`.
Merge pull request #181 from github/fix-xcodebuild

Remove RunUnitTests scripts
++xcconfigs
Update objc-build-scripts
Don't pass in -sdk (for Travis)
Revert "Don't pass in -sdk (for Travis)"

This reverts commit f4633f60bafd4dcc0370aaed15bf4eb4174dbf5a.
Update objc-build-scripts
Merge pull request #182 from github/xctool

Build with xctool
++xcconfigs for arm64 support

CC @bdolman
Include 64-bit build in iOS library

Remove the explicit ARCHS override for the iOS target in favor of using
the default base configuration ARCHS that includes 64-bit support.
Merge pull request #186 from bdolman/master

Include 64-bit build in iOS library
Specta/Expecta -> XCTest
Remove now-defunct mtl_firstObject
Add MTLPropertyAttributes class to replace extobjc methods
Move away from extobjc
Remove deprecated methods.
Remove unused comparison additions.
Remove code for "old" MTLModel+NSCoding archives.
Simplify MTLSelectorWithKeyPattern.
Remove unused inversion extensions.