Do not leak memory when handling cache manager requests (#1408)

Do not leak memory when handling cache manager requests (#1408)

Also adjusted Cache-Control APIs to prevent similar bugs. These changes
also speed up processing a bit and simplify most of the affected code.
The now-gone "just remove the old CC" putCc() misfeature was unused.

The leak was introduced by commit 92a5adb: PutCommonResponseHeaders()
incorrectly assumed that putCc(pointerToX) takes ownership of X.

Detected by Coverity. CID 1534779: Resource leak (RESOURCE_LEAK).