- Completed WaitOnAccept

- Completed WaitOnAccept
- Rewritten all the WaitXXX functions so that they do not depend on the
event notification system.
- Rewritten all the internal event system; now all events are internally
monitorized, but users are notified only of these events they are
interested in. This solves a lot of hard-to-catch little problems
and bugs which could arise sometimes.
- Rewritten all the automatic event notifier code.
- Added callback management code, which had been forgotten (badly needed
for wxTCPConnection in IPC classes)
- Fixed wxSocketBase::Write(), which didn't honour the WAITALL flag.
- Fixed some other bugs.
- The code is now much more stable and robust than before (because
the architecture is more robust, but it still needs testing).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3613 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775