altgr+shift/capslock support in keymaps

Currently xrdp handles only lowercase national characters. These patches add support for shift+altgr (there was some support in genkeymap but nowhere else for that), capslock+altgr and shift+capslock+altgr. It also enables generation of Polish keymap.

I have regenerated all the keymaps in the last commit but my system seems to give different results than the original one where keymaps were generated. You may want to regenerate them yourself.