Support for UTF-8 mouse input (\033[1005h). This was added in xterm 262
and supports larger terminals than the older way.
If the new mouse-utf8 option is on, UTF-8 mouse input is enabled for all
UTF-8 terminals. The option defaults to on if LANG etc are set in the
same manner as the utf8 option.
With help and based on code from hsim at gmx.li.
Move the user-visible parts of all options (names, types, limit, default
values) together into one set of tables in options-table.c. Also clean
up and simplify cmd-set-options.c and move a common print function into
option-table.c.
