Adding failure message path for tangelo widget if JQuery UI not loaded.
Bundling correct version of autobahn with Tangelo as subpackage.
Changing websocket module to use bundled autobahn.

This fixes an interface change in a newer version of autobahn.
Simplifying code for vtkweb example.
Implemented vtkweb clientside API.

Changed example over to use API - cone example works.  Some more tweaking
required to make phylotree example work.
Got commandline args to work (i.e., the phylotree example).
vtkweb API supports relative pathnames.
Converted path argument for vtkweb POST to query argument.
Merge branch 'clientside-vtkweb'

Closes #213.
Removed all extraneous files from vtkweb example.
Removed phylotree example (moved to xdata-app-pack repo).
Merge branch 'simplify-vtkweb-example'

Closes #170.