Modify drive_pattern regex to recognize UNC paths (leading "\\").

[jmm]

This fixes issue #118 -- do you foresee any unwanted side effects?

I think technically it's unnecessary to include the ^ (and stemming from that the parens) in the regex if you only end up calling match() on it (?), but I left it and added the parens.

There's also a commit here that eliminates some trailing whitespace that was already present.

[ryanpcmcquen]

I've merged your fixes into my fork: https://github.com/ryanpcmcquen/SublimeTextXdebugPlus

Which I am attempting to get into Package Control: https://github.com/wbond/package_control_channel/pull/7658