update to cross section tool

danames[CodePlex]
The cross section tool (by gwerner) needs to be updated as follows:

Use the same graph tool as the HD graph plugin Use the same modality/ownership so it stays in front of HD but not in front of other stuff - like the feature identifer
Add ability to double click to close Change to click click click to draw multiple segments

Start by locating the cross section tool and the HD graph plugin, then compare their graph behavior and modality/ownership settings. Verify the requested window behavior and interaction flow: double-click closes the tool, while successive clicks draw multiple segments.

Written by the indexing model from the issue text.