[PATCH libxkbcommon 2/2] README: Add basic build directions

[Ran Benita]

On Thu, Sep 15, 2016 at 02:31:55PM -0700, Bryce Harrington wrote:
> In particular, highlight the use of configure flags to control locating
> X11 keyboard stuff when building for Wayland.
> 
> Of particular note, if the locale root is not specified, then xkbcommon
> will look for them under $prefix (i.e. /usr/local/share/X11/locale).
> But unless the user has specifically installed them there, it is better
> to look in the standard system location, /usr/share/X11/locale.
> 
> Otherwise, xkbcommon will error when it can't find them, e.g.:
> 
>   xkbcommon: ERROR: ~/.XCompose:4:9: failed to expand %L to the locale Compose file
>   xkbcommon: ERROR: ~/.XCompose:4:12: unterminated string literal
> 
> Signed-off-by: Bryce Harrington <bryce at osg.samsung.com>

I applied these two as well, thanks!

BTW: The xkb-config-root is usually taken from the xkeyboard-config
pkg-config file, so it's usually not problematic if you have
xkeyboard-config installed during the build.

The x-locale-root is more unfortunate since libX11 does not provide a
pkg-config variable for it. IIRC I tried to add one (and even split the
x-locale stuff to a different repo since the Compose data is useful for
other projects well), but it was ignored... Hopefully distros can split
the libX11 package themselves though.