Remove unnecessary debug output.
Fix "open" action such that the new content is shown (i.e. tab becomes active).

Also turn off broken persistence.
Try integrating coverage CI.
Add coverage checking for CGM too.
Fix travis.yml format (no tabs allowed)
Add support for Polygon rendering, plus fill colour.
Add support for rendering ellipse.
Remove stray debug output.
Add test file for circular arcs.
Fix edge type handling for filled primitives.

The test case for this isn't working (doesn't actually draw arcs yet), but it does demonstrate this problem.
Correct orientation. We were previously drawing upside down.
Correct drawing of Graphic segments after fixing orientation in CGM module
Add circular arc centre support.
Add proper background colour support.
IMG-16: Add support for additional TRE definitions.

Also remove left-over NitfFileFactory bits, which we're really pulling their weight any more.
Generalise the TRE parsing approach so that it should work OK everywhere.
IMG-16: Remove unneeded initialisation check.
IMG-28: Rename "Open" action to be "View" action.
IMG-27: Add support for display of NITF 2.0 symbol segment CGM.

Also refactored some existing "TODO" data source code that was common between Graphic, Image and Symbol segments.
IMG-24: Add references for newly created "TODO" tickets in JIRA.