Updates - Thanks for all the enhancement suggestions!

This fixes a few small bugs, most pertinently the fact that some rules would cause Ruler to crash during the "display rules" phase.

Added some enhancements that were suggested through the issues tracker. Thanks!

• adds --proxy support for brute forcing
• displays progress during brute force
• uses username as password during brute force (once all possible username/password combinations have been tried. Does not apply to --userpass)
• Tries to use InternalURL if there is no ExternalURL available in the autodiscover.xml