wm2 Code

* Update README and UPDATES file
* Make the configure actually do something if a requirement is not
found!
* Remove some obsolete doc bits

* Oops

* Add note about CONFIG_NO_BUTTON

* Patch from Ben Stern via wmx mailing list, to apparently reduce the
chances of losing keyboard focus when switching channels away from
certain applications. Not yet tested. For some reason I never
received the email with this in it, I've only just found it in the
list archive.

...

* Include hidden clients in stacking list -- panels/taskbars/etc seem to
expect the same clients in both stacking and client lists

...

* some more minor updates

* expose border when client label changes
* more debug out

* Fix bug that was causing palette type windows (above layer 7) to get
left behind when switching channel
* Add handling for eventMap without eventMapRequest -- some GTK options
windows appear to make extensive use of this for some reason I don't
fully understand
* Improve reporting for list out-of-bounds errors, and avoid crash if
for some reason the ordered list for a client's layer turns out to be
empty
* Better interaction with WM_CHANGE_STATE from task bar
* Fix failure to tidy up properly on exit
* Lots of debug output currently enabled