Quiet undeclared selectors warnings in Test builds

Otherwise, there are warnings about -beforeEach and -afterEach.
Pull up prefix header settings to project
Deduplicate compiler version settings

This is already set at the project level
Pull up validate product setting to project
Pull up framework search path setting to project
Deduplicate architecture settings

Just of OS X builds
Merge pull request #10 from kastiglione/test-build-warnings--

Quiet undeclared selectors warnings in Test builds