Some fixes

* make qt configuration in CMake more flexible
* move creating of symlinks on windows from post build event to cmake
* create symlinks for test data in cmake on windows
* switch to 7zip for extraction python indexer
* make results of sourcegrouptests case insensitive

bin/test/data/SourceGroupTestSuite/cxx_cdb/expected_output/output_windows.txt

@@ -1,5 +1,5 @@
-SourceFilePath: "src/Test.cpp"
-	IndexedPath: "src/Test.cpp"
+SourceFilePath: "src/test.cpp"
+	IndexedPath: "src/test.cpp"
 	IndexedPath: "test/indexed/header/path"
 	CompilerFlag: "clang-tool"
 	CompilerFlag: "-fms-extensions"