logic: File Manager

* added FileManager that keeps track of the files analyzed by the project. It therefore checks if files get added, updated or deleted from the source- and include folders.
* refactored ASTVisitor::hasValidLocation() and implemented one version that search for the location in the currently parsed file and one that searches in all the project's source files.
* quickfix: switched order in FileManager so that header files are parsed first.
* created folder for helper classes used in tests.
* added test code for FileManager
* adjusted test code for Parser Tests.

src/test/helper/TestStorage.cpp

@@ -0,0 +1,18 @@
+#include "TestStorage.h"
+
+#include "utility/text/TextAccess.h"
+#include "data/parser/cxx/CxxParser.h"
+#include "TestFileManager.h"
+
+void TestStorage::parseCxxCode(std::string code)
+{
+	clear();
+	TestFileManager fm;
+	CxxParser parser(this, &fm);
+	parser.parseFile(TextAccess::createFromString(code));
+}
+
+const Graph& TestStorage::getGraph() const
+{
+	return Storage::getGraph();
+}