SCPlugin work in progress

Well, due to a double fracture in my left arm, I'm homebound for until the end of April. Due to that, I'm picking up some Open Source development work. As a member of the SCPlugin team, I will try to get an initial Subversion repository checkout working, where the login credentials will be asked in the user interface. With repositories that required authentication, one had to use the command line client for the initial checkout.The goal here is to implement an authentication provider for Subversion similar to the prompting command line client, but one displaying a login panel. You can follow the progress on the ui-auth branch.