Xorg Options Editor GTK UI should follow the Gnome HIG

[Alberto Milone]

Binary package hint: xorg-options-editor-gtk

As discussed with Matthew Paul Thomas, Xorg Options Editor GTK UI should follow the Gnome HIG.

* It shouldn't have any secondary dialog at all.
* The list containing "ServerFlags" and "Configured Video Device" should be an option menu that sits above the table. This will make the table wider.
* The option description shouldn't be displayed twice. It should be removed from the
table, leaving it only in the separate frame underneath.
* The first column of each table row should be an option menu listing the
available options. This way there's no need to open a dialog to choose
the option; instead users should just select it from the menu. Something similar to the address section of Thunderbird's message composition window.
* The second column of each table row should be editable, so that users can enter the value directly. If the required value is a boolean, we should make it another option menu with "True" and "False" options. If it is an
integer, we should make it a text field that only lets you type digits, with spinbuttons for incrementing and decrementing. If it is a string, we should make it a normal text field.
* Instead of using an "Add" button, users should press Enter in the last row, or click underneath it. Instead of a "Remove" button, let's use the Backspace or Delete keys. Instead of an "Edit" button, just click on a value and edit it.
* The Driver and Screen elements should be left-aligned