Enlarging canvas when needed.
Resized event class.
Mouse multi selection for canvas.
Eliminated warnings when importing schema.sql into Virtuoso, closes #995.
Fixed a typo in logged message.
Pipeline conflicts are copied with pipeline, closes #1015.
Multiselect on canvas and resizing when needed.
Merge branch 'master' into improved-canvas
Added implementation of save/load methods into FileDataUnit
Added check for non-null DPUContextInfo. #1277
Resizing of canvas with window resize. #1258