qemu-char: add missing characters used in keymaps

This patch adds all missing characters used in regional keymap
files which already exist in QEMU. I checked for the missing
characters by going through all of the keymaps and matching that
with records in vnc_keysym.h. If the key wasn't found I looked
it up in libxkbcommon library [1]. If I understood it correctly
this is also the same place where most of the keymaps were
exported from according to the comment on the first line in those
files. I was able to find all symbols except "quotebl" used
in Netherland keymap.

I tested this update with Czech keyboard by myself. I also asked
Matej Serc to test Slovenian keyboard layout - he reported problems
with it few days ago on this mailing list. Both layouts seems
to work fine. I wasn't able to test the remaining layouts but
since this change doesn't modify any existing symbols, just adds
new ones, I don't expect any sideeffects.

[1] http://cgit.freedesktop.org/xorg/lib/libxkbcommonSigned-off-by: NJan Krupa <jkrupa@suse.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>