Bug 423018 - Direct Graphiti diagram exporter

* Introduce possibility to export a diagram as an image without opening
an editor
* Add example export as image context menu entry to context menu of
diagram files in explorer
* Allow the export also in case the Graphiti tool for the diagram type
is not installed
** Render images by using a default "not available" image
** Render platform graphics algorithms as "not available" shapes

Change-Id: I25ee2edca1e204322ff4cea191be2a68d4545ac7
13 files changed
tree: 3f8701e1ecca974e6f02ca89bd7689b8fb705145
  1. CONTRIBUTING.md
  2. examples/
  3. features/
  4. parent/
  5. plugins/
  6. releng/
  7. tests/