Remove CMake options page - use existing build path instead
Connect CMake provider as a plug-in
Revert "Remove CMake options page - use existing build path instead"

This reverts commit 122378075b6e4c5b421d2488b94edf68af6f6759.
Fix some loose ends. CMake provider should now work, once the XML
parsing is in place.
Start work on CMake XML parsing