All frame file I/O uses the same directory load/save location but DBC files store separately as do filter files, graphing definitions, and stored text files from the various reverse engineering windows.
* improves window handling a lot
(on Linux GNOME 3 at least: quickly resizing windows left/right, not forced in foreground anymore etc.)
setWindowFlags() inserted in all *window.cpp files except mainwindow
* some whitespace at EOL trimmed