Work in progress - SVG library adaption

Started using some of SVG functionality. Question remains whether to
draw everything in the workspace as SVG or use it only to draw the
lines.
Lines in progress

Lines now are simply drawable and updateable. Next step: in and out
ports should be connectable by lines.
Lines can be dragged correctly.

Lines can be dragged correctly from out ports. Next step is to snap them
to valid in ports and leave them in place if they connect.
Snap(ple) in progress

Snapping seems to work visually, but the underlying functionality still
needs to be fiddled with.
Correct snapp(l)ing
Merge remote-tracking branch 'origin/master' into Workspace---Nodes-and-Lines

Conflicts:
	mockup.css
	mockup.html
	mockup.js
Merge remote-tracking branch 'origin/Workspace---Nodes-and-Lines'

Conflicts:
	mockup.css
	mockup.html