Select and drag text labels with nodes.

Better rotation. fixes #61
Invert selection; delete nodes and text labels together
Composed PlacedDiv for placement of HTML elements on SVG container.
citing escher FAQ
Moved to beta 3; took cofactors out of cobra model json.
Don't clear cache during testing
Add, edit, delete, and undo/redo text labels.
Fixed bug: incorrect placed_div name in build input
Streamlined drawing; huge speedup for deletion; still separating beziers.
Beziers have their own layer.

Still unfinished. See Map.js#L1131.
Move beziers with rotation; add beziers with new reacitons.
Better offline homepage. Fixed single node selection.
Added no data styles. Clamp size scales.
remove little black anchors, borders on SVG export
Are you sure you want to quit? message.

The new option is: never_ask_before_quit.
Parse URL in javascript for static site generator.
Convert map_name & model_name to paths for static site.
Fix for urls
fixed static cobra model call
non-minified static files