Fix <form ...> definition in system.php.
Fix minor bugs (e.g. action="..." was empty).
Remove useless code (dhcp lease handling is not needed on client).
Add copyright notice.
Modify gui.
Add gui.css to svn.
remove useless code. improve file chooser.
Improve filechooser code/design.
Add missing translated text. Rename translation file.
add file chooser.
