Add pygeo as submodule
Split out VCS and DV3D plots into separate plugins
Resolve vcs module naming conflict

The vcs module is not contained in any package. This means that it
can't be import from inside a plugin module called vcs. To resolve
this import vcs in the uvis package to give it a package. It can
then be imported using 'from uvis import vcs'
Fix PlotFactory createPlot(...) function

Rather than creating the factory object, call the registerd "create"
function. Raise a RuntimeError if type has not been registered.
Clean up uvis.sh startup script
Add missing error callbacks

Add error callbacks to log errors to console.
Remove debug statement
Move pygeo forward