Replaced the icon set with simpler countour-only images(closing #11). Also, by default now there is no vertex label text.
1) Added code for loading an image background for the graph (# 12). 2) Added two Hi-Res built-in images (a map of the UK and a world map). 3) Restored the previous (full-color) icon set along with the outline icons (with some slight modifications). The reason is that they look better on the map. 4) Reordered the vertex context menu. 5) Added options to select the background image (including loading from a file) and to change the graph background & edges colors to the general context menu (when right-clicking outside a vertex / edge).
Merge remote-tracking branch 'origin/vladi' into develop
Reduced the resolution of the built-in maps to 50%. Also set the simple icon style as the default.
Reduced the simple icons size by a very small factor in order to make the separation between nodes more pronounced when there are multiple adjacent vertices.
Merge branch 'vladi' into develop
Added unit test for some of the methods in Stats and fixed APL computation.
Added weighted average path computation. Had to create an extra event that is fired when edge weight is set via the GUI to trigger a recalculation of all statistics. Also, edge weight must now be set through the graph and not through the edge (otherwise a change event will not be fired). Closes #2
Simplified the ExtraGraphEvent hierarchy by removing all subclasses
Fixed bug where min/max edge weight was displayed in GUI instead of min/max degree