util: Add keymaps.csv

util: Add keymaps.csv

Should keep it as the same as:
http://git.gnome.org/browse/gtk-vnc/commit/src/keymaps.csv

All master  keymaps are defined in a CSV file. THis covers
Linux keycodes, OSX keycodes, AT set1, 2 & 3, XT keycodes,
the XT encoding used by the Linux KBD driver, USB keycodes,
Win32 keycodes, the XT encoding used by Xorg on Cygwin,
the XT encoding used by Xorg on Linux with kbd driver.

* src/Makefile.am: added to EXTRA_DIST
* src/util/keymaps.csv: new file