This commit is very similar to 8c8853a1

We update the keynames.txt file from gdkkeynames.h, and we update
keynames-translate.txt to include all the keysym names that we want
to have translations for. Also strip the XF86 from the translatable
keysym names, since we are returning those names now from
gdk_keyval_name().

keyname-table.h is regenerated from these updated files.