Better documentation for the command "windowlist" and "windowlist-by-class".
Moved the initialization of the optional arguement "window-list" of the command "windowlist" from the lambda-list to a let form in the body of the command.
Merge branch 'master' of https://github.com/stumpwm/stumpwm
Fixed doc generation:
Updated the docstrings of *window-info-format*, *window-format-by-class*, windowlist and windowlist-by-class.
Added the missing nodes in stumpwm.info.in (*window-info-format* and windowlist-by-class)

Plus: slightly optimized xwin-type function.
Merge pull request #168 from mpsyco/master

Better documentation for the command "windowlist" and "windowlist-by-cla...