increase line thickness for tree comparison

The output of tree comparison now has thicker edges.  This makes
it easier to see the colors that have been assigned to each edge.
enable analyses on tree outputs

Before this commit, the resultTree from fitContinuous was created
as a view.  This meant that no further analyses could be performed
on it.

To fix this, I modified GeigerFitContinuous.xml so that this output
tree is created more similarly to the output table.  I also modified
voRemoteCustomAnalysis.cpp so the output tree is created as a
voOutputDataObject.  After doing this, the voDataModel now
automatically treats the output tree as an output (and not a view).

While working on this, I noticed that voCompareTree was also
creating its output tree as a view.  I also fixed this, so that
further analyses could be performed on this output tree as well.
fix memory leak in remote R calculation
Merge branch 'improve_tree_comparison'

* improve_tree_comparison:
  fix memory leak in remote R calculation
  enable analyses on tree outputs
  increase line thickness for tree comparison