Merge pull request #276 from jay-hodgson/shiny-whitelist

include shiny.synapse.org in whitelist
SWC-541: horizontal rules
Merge pull request #275 from jay-hodgson/SWC-489-round2

SWC-489: pull heading inner html to style ToC items
javascript callback to a java method, must use xhr.upload.onprogress
SWC-523: move shiny to alpha and SWC-452: target markdown tables
Merge horizontal rule detection into release-1.24
Merge determinant progress bar into release-1.24
Merge alpha shiny widget and markdown table css targetting into release-1.24
Merge pull request #280 from jay-hodgson/release-1.24

Merge in code reviewed changes