Fix #3 by by adding margin space to allow clicks

Added a small margin to the right of the bpmnio diagram. This solution is not so nice however...

Fix: base64 decoding in JS for non ASCII chars

Fix: properly decode the base64 encoded string

UTF-8 encoded into base64 did not decode well. Characters were destroyed. Javascript needs some more layers of transformation to get it right.

Fix: HTML entities inside XML are now usable

Decode base64 data (lossless)

Encode data using base64

Added a screenshot for the plugin

Improved: Refactored the code for the viewer

Improved: Adjusting the viewbox to recenter the diagram

Integrated the renderer for in-page, embedded bpmn xmls

Adopted the same license as bpmn.io
(MIT+logo conservation)