Render from command line

[rodlie]

Need to render project from command line for unit tests etc.

• [ ] project file name
• [ ] scene index/name
• [ ] resolution (%)
• [ ] dimensions (w/h)
• [ ] fps
• [ ] frame start
• [ ] frame end
• [ ] encoder profile
• [ ] output file name

[rodlie]

Feature delayed until #37 is done