Improved node separation and general bugfixes/enhancements

• Improved node separation for larger trees
• Fix scroll locking bug when zoom is disabled
• Color NaNs in white in collapsibleTreeSummary and warn user
• Support single node tree in collapsibleTreeNetwork
• Namespaced CSS to not interfere with other htmlwidgets
• Include test dependency tibble in "Suggests" per new CRAN policy

collapsibleTreeNetwork, Mappable nodeSize, and HTML tooltips

• Added collapsibleTreeNetwork for use with network-like data frames, such as org charts
• Map node size to any numeric column
• Add custom tooltips (possibly containing html) to collapsibleTree.data.tree
• Optional pan and zoom for chart
• Added option to have tree uncollapsed at start
• Added percentOfParent parameter to collapsibleTreeSummary
• Consolidated collapsibleTree methods docs

Varying tree depth

• Support for trees with varying depth, by using NAs for values in the hierarchy
• Support for using data.tree objects in addition to data frames

Automatic chart sizing

• Chart margins are now computed at render time rather than with a preset value. Calculation is based on label length and font size to give appropriate padding for labels on both sides of the chart.
• Link length is now computed at render time rather than with a preset value. Calculation is based on the chart width (minus the padding) divided by the number of nodes. This can still be overwritten in the options.
• Under the hood, the javascript bindings have been restructured such that instance properties are now accessed as a property of the widget, rather than being passed around by functions. This makes tracing data flow quite a bit simpler.

Added tooltips

• Optional tooltips that map to the same attribute as the color gradient, or a different attribute if you're not using gradients.
• Removed unnecessary JSON fields that were passed to client

Node color gradients

• Added collapsibleTreeSummary to more conveniently construct node color gradients based on either the number of children or a column in the data frame
• Responsive chart sizing
• Negative weights are handled like 0 rather than throwing an error

Customizable node colors

• Custom node fill colors
• Different instances of collapsibleTree no longer interfere with one another
• IE 11 support

Initial release

• Added Shiny input bindings