Tests: Add unit tests for CSV import

Add a new test class for testing the import functionality. Currently
it's only covers some test cases for the CSV import.

Since the function to test here (DBBrowserDB::decodeCSV) is part of the
DBBrowserDB class, that class has a reference to the main window and the
main window basically depends on the entire rest of the project the
makefile grew quite a bit unfortunately.
Fix stupid spelling mistake in the default gen_version.h file

Fix a spelling error in the include guard of the default gen_version.h
file. It didn't really matter even though this exact file is used when
building with qmake because it never gets included multiple times... but
it just looked odd to me and was a bit annoying since I noticed it :)