fixed one scale bug where between 1 and 2 resulted in no actua scaling

Conflicts:
	printrun/projectlayer.py
fixed scaling bug; updated cairosvg to latest version

Conflicts:
	printrun/projectlayer.py
Remove cairosvg from repo, add it to dependencies
Fix import of cairosvg
Update README.md a little bit
Update README.md, add requirements.txt for Printrun