- Create a session_t structure, to get rid of most global variables and
let information pass in/out mostly through parameters. Huge changes,
so bugs may very well appear. I'm worried about resource leakages, in
particular.
- Add gcc attributes on various functions.
- Add Doxygen configuration.
- Replace much Xlib Bool with C99 bool.
- Add and adjust some comments.
- Drop unused parameters from some functions.
- Cache default Visual and Depth, mainly to shorten code.
- Rename some types, variables, and functions.
- Add win_ev_stop() and set_ignore_next() for convenience.
- Modify wid_get_prop_wintype() and wid_get_opacity_prop() to use
wid_get_prop().
- Rename --respect-attr-shadow to --respect-prop-shadow.
- Fix a memory leak in --respect-prop-shadow.
- Many other small changes.
