Repairs podspec
Repairs podspec

Brings back previous notion of Extensions
Invasive stubs should go in the stubs group/target/sub-spec

mjstallard/PivotalCoreKit,gudatcomputers/PivotalCoreKit,briancroom/PivotalCoreKit,joemasilotti/PivotalCoreKit,jfuchs/PivotalCoreKit,idoru/PivotalCoreKit,jfuchs/PivotalCoreKit,pivotaltracker/PivotalCoreKit,idoru/PivotalCoreKit,joemasilotti/PivotalCoreKit,pivotal/PivotalCoreKit,gudatcomputers/PivotalCoreKit