Language file support for DWT

[Frank Benoit]

For the SWT part of DWT, I added the language files and support for
accessing them in dependency of the current locale. (HG repositories)

Test program:

import dwt.std;
void main() {
	Shell shell = new Shell(Display.getDefault());
	MessageBox.showMessageBox(
		"Dummy text",
		"Title",
		shell,
		DWT.ABORT|DWT.RETRY|DWT.IGNORE|DWT.ICON_QUESTION );
	Display.getDefault().dispose();
	return 0;
}

To compile, please notice that now a new compiler switch (-J) is needed
for the new resource directories in dwt-win/res or dwt-linux/res

Please test if it works for you in your language.