Improved GraphML import capability to import more info from graphml files produced from other software (now imports color and position data from Gephi):
- keyInfo dict now maps to a new dict that uses the 'for' attribute to map to the attributes dictionary. This allows for keys with the same id to map to different keys depending on if the key is for an edge or a node. If no 'for' key attribute is specified, 'forNotSpecified' is used to map to the corresponding dictionary.
- Can now import color data using either 0 to 1.0, 0 to 255, or hex for RGB values. Color can be named either 'r', 'g', 'b'; 'red', 'green', 'blue'; or 'fill'
- Can now import vertex and edge size data that is either named 'size' or 'radius'
- Can now import vertex label data that is either named 'name' or 'label'
- Added ImportError for edges whose source and target are the same
- Added comments