Updated for use with homebrew's installation of doxygen.
Added proper support for Xcode 5 DP3. Currently it seems as if the harness was failing to invoke the deprecated -[NSException failureInFile:atLine:withDescription:] method, which seems to be (1) private API and (2) deprecated as of Xcode 5 as the transition to XCTest begins. In any case, under Xcode 5DP3, the harness was reporting back a nil selector which would mess up test case failure reporting.