commitmonitor Code

This is a bigger change:
* only use one instance of CUrlInfos
* pass around that one instance to wherever it's needed
* guard the data in CUrlInfos with critical sections
* make sure the data is guarded only for short times
* in the monitoring thread, use a copy of the CUrlInfos data because of the point above

Keep track of the main dialog shown. If it is shown while the thread is running, discard (do not save) any change in the url data which the thread might have done.

Try to stop a possible running thread gracefully before exiting the process.

First non-working version of parsing the html page from an SVNParentPath url.
Got the downloading part working now after several hours of trying.

* create the main dialog with passing a parent window
* in the main dialog, send a message to the parent window when an unread message is shown so the parent window (the hidden window) can change the system tray icon to 'normal'.

* allow only one instance per user
* add a tray icon

* get rid of the boost serialization (that one crashed and I couldn't figure out why), implement our own serialization instead.
* Implement timers and threads to fetch the log data and check for updates according to the settings.
* Implement username/password to pass to the repository if necessary.

Add a hidden 'main' window which handles the window messages and the icon in the tray area.