Made the instance of moment.js packaged with vis.js accessibly via `vis.moment`.
Merge remote-tracking branch 'origin/develop' into develop
Implemented option `minHeight`, similar to option `maxHeight`. (See #132)
Added a simple navigation menu example
Added function `repaint()` to force a repaint of the Timeline.
Fixed #116 and #138: bug when rendering the Timeline inside a hidden container.
Fixed #86: A newly created item is now initialized with `end` property when option `type`
  is `"range"` or `"rangeoverflow"`.
interchanged canvasToDOM and DOMtoCanvas to correspond with the docs.
Merge branch 'develop' of https://github.com/almende/vis into develop

Conflicts:
	dist/vis.js
refactored _canvasToX to _XconvertDOMtoCanvas and _xToCanvas to _XconvertCanvasToDOM (same for y)
Merge branch 'develop' into linegraph

Conflicts:
	dist/vis.js
	dist/vis.min.js
	src/graph/Graph.js