Update 1.3 (LÖVR support & more)

I've been messing around with LÖVR for the past few days, so I figured I'd update loveman to add support for it as well as do some other maintenance work to it!

• Added support for LÖVR projects, making VR development a breeze!
• Slightly redesigned the UI to be a little bit more modern. Yay, we're in the future!
• Moonscript is now included with Loveman, so you don't have to manually enter the path to Moonscript anymore.
• Since LÖVE has fully switched over to Github, the release building dialog now downloads LÖVE binaries from Github instead of Bitbucket.
• Loveman is now open source! You can find the source code on Github.