Run tests on 32 and 64 bit
ensure failures on pipes and subcommands

Makefile makes a new shell instance for each new line.
If xcodebuild failed with 65, we were still exiting with 0
Import TestClass.h in KWFunctionalTests
Use __typeof__ to determine smarter let variable type
Merge pull request #528 from kiwi-bdd/let-type

Smarter let types