events

[Marius Nita]

some thoughts on event handling:

- have a OEvent base class
- have OXEvent and OSignalEvent derived from this class

we have an event queue in the wm. when an X event comes into the event_loop,
it's wrapped into a OXEvent and stuck at the back of the queue. Signal
handlers to the same thing: wrap the signal into OSignalEvent and stick it at
the back of the event queue. if we need other types of events, they'll be easy
to incorporate into the scheme of things.

this way we handle signals and events in the same manner.

there's a OEventHandler base class which all event-handling entities extend.
this is like ob3's XEventHandler, except it deals with signal events too.

actual event handling from the queue is a matter of poo->handleEvent(event),
where event is treated as an OEvent opaquely.

anyway, something to think about
marius

PS: let's discuss the toolkit, and how we plan to handle screen info and
colormaps now that basedisplay will go away. (yay)