commitmonitor Code

* use a better, reentrant reader/write section class
* refresh the UI in a timer interval

Handle the WM_TASKBARCREATED message.

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.

* Only load the info data from disk when the thread starts.
* Don't save the url info data as long as the main dialog is visible.

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

Delete all diff files when a monitored URL is removed.

Don't check projects which don't have updates every minute but only after another time interval has passed.

Trim the trailing slash from the SVNParentListPath projects name.

Canonicalize the urls before adding them to the monitoring list.