Changelog:
* Remove build of Phobos and Proxygen from Deimos build script - has to be called separately now before building Deimos!
* Update noinstall-headers of Phobos for new Phobos & Deimos version
* Change CMAKE_PREFIX_PATH in Deimos (didn't work before) and add CMAKE_EXPORT_COMPILE_COMMANDS
* run Deimos tests as Cmake targets
* Change PowerTools to powertools