Merge pull request #193 from jay-hodgson/develop

SWC-386: handle all encode/decode for widget parameter values
The people have spoken, we need to support (some) html in the markdown. strip out a set of potentially dangerous html tags: SCRIPT, OBJECT, APPLET, EMBED, FORM
Merge branch 'develop' of https://github.com/Sage-Bionetworks/SynapseWebClient into develop