SWC-674: big button link widget in alpha area
SWC-674
SWC-674: add to main widget collection, not in alpha
Merge pull request #403 from jay-hodgson/develop

SWC-674: Merge button link markdown widget down to develop from release-1
Merge branch 'develop' of https://github.com/Sage-Bionetworks/SynapseWebClient into swc-81
lightweight home page part 2