XCTest: Support Static Libraries

XCTest is limited to logic tests within static libraries, but it does support that much. It seems support for it was omitted from the XCTest module. Often because it is limited developers will simply wrap their static library in a bundle of some kind for testing, but if you have a large number of small static libraries it is useful to have fine grained logic tests, and an overarching bundle for other tests. Wrapping in this case clutters the xcode project significantly. This patch allows logic tests to be added for static libraries in xcode.

Superseded by !732 (merged).