[BUILD] made OpenMS compile again

 * customised variables to point to correct locations
[BUILD] removed obsolete qt hack
[TEST] fixed test data path
[BUILD] proper exposing of include directories and libs for sibling projects
[BUILD] moved some general build system code to top-level project
[BUILD] moved doc related stuff to separate CMakeLists.txt in doc folder (non-functional)
[BUILD,DOC] moved all doc related code to the doc/CMakeLists.txt file

 * fixed some doc related build issues
[BUILD] moved some more build system config from the openms/CMakeLists.txt to the top-level CMakeLists.txt
[BUILD] moved OpenSWATHAlgo into a separate directory
[NOP] reformatted contrib finding
[BUILD] moved topp/utils to separate directory/project
[BUILD,TEST] moved tests to separate projects
[BUILD] more test restructuring
[BUILD] moved class tests to a separate directory

 * XMassFile_test doesn't compile, fix in follow-up commit
[BUILD,TEST] added test_config.h which manages finding of test files
[TEST] fixed class tests referencing files from the TOPP test data directory
[INTERNAL] fixed findDoc() w.r.t. to the new layout
[TEST] fixed XMassFile_test by removing the data include and replacing it with reading of test data on execution
[BUILD,TEST] reenabled topp tests
[BUILD] moved gui code to openms_gui