Fixes -Warc-performSelector-leaks in KWIntercept
Fix arc flags for KWStub and KWIntercept for XCTest target, aded missing headers to XCTest target
Removed SenTestSite additions from XCTest target’s copyFiles.
Merge pull request #469 from jessedc/xctest-target-fixes

-Warc-performSelector and XC-Test target fixes