(Closes issue #152) : Use Snarl popups
* include the snarl API
* use snarl to show a popup if it is running, otherwise still use the CommitMonitor popup as usual
* include the png resource in the installer for snarl to use
(Closes issue #156) : Installer should remember previous install location
* save the install location in the registry and make the installer use it if available.
(Closes issue #184) : Allow to mark a change as new/unread
* add command to set the state of an item as unread.
* only mark an item as read when the item gets selected, not unselected.
(Closes issue #168) : Own commits aren't displayed in the change log immediatelly after the project was checked for commits
* Refresh the list control if there are new unread entries too.
* Fix bug when refreshing entries if all log entries were removed.
