VM keyboard layout selector

[florian-krueger]

There is a new menu entry "VM key layout" (can this be hidden for enhanced mode?). To make this work I needed to extend the network interaction for keyboard actions to include on each key hit the currently configured layout. I changed the separater from "-" to "_". So each keyboard event looks like "145_1_en-us".

Issues:

• Not sure if it is great to have another entry in the main menu
• The keyboard mappings are now in front-end for the text typing function. So we have two mappings: char to KeyCode per keyboard layout and KeyCode to ScanCode per keyboard layout. Could this be unified somewhere?
• When connecting to a VM, is there any chance to find out the input layout in the VM? Another option would be to store the chosen layout in cookies so it stays the same after reconnect - maybe per VM ID?