Previously we were inconsistent by generating code for enum definitions
but not generating code for dictionaries. With future changes to the
IDL generator to expose helpers to convert to and from IDL values
this produced circular depdendencies. To solve this problem, also
generate the dictionary definitions in bindings headers.
In this case, we should just draw a line from the last point in the
path to the start point. Previously, a division by zero caused nothing
to be drawn.
