processing of parts and the GUI were split into different procedures

the implementation of Taraniselsu's idea to
"- Maintain our own list of parts with the information that we want
(name, mass, cost, resources, etc)
- Watch for GameEvents and update the list whenever the vessel changes
- DrawWindowContents would loop through our list of parts and display
the information in the window"
GUI: print "-" instead of "0" for Mass and Cost of parts that do not contain any resources

Some parts doesn't contain any resource or has maxAmount of all
resources equals to 0 (for example the electricity generators or
consumers of fuel, such as engines).
For such parts it is seems better to print mass/cost of resources as "-"
not "0"