[merge request] many new sawfish patches

[Teika Kazura <teika lavabit com>]

Hi, please merge my sawfish branch. It includes:
* Better error message. Phrase "Sawfish error:" is prepended to error
  messages printed to standard error. 
  This helps if the Sawfish output is mixed with that of X server and
  so on.
* Made `sawfish-config' minimal, moving most of the contents to
  sawfish.cfg.shell. This facilitates hacks.
* `x-atom-name' accepts full 32 unsigned int. Previously only 30 bits are
  treated, if the architecture is 32-bit.
* Doc. E.g. improved manuals (1), where all options are now described.
* (I'll explain this later.) Prints backtrace for sawfish-client, too.
  This makes sense if you're using librep >= 0.90.7. No effect otherwise.

Keyboard layout switching patch (and one more) will be sent next time.

And so on.
Teika (Teika kazura)