Object oriented model

[l0b0]

We should probably move to an OO model soon - There are too many parameters which are just relayed by mian() to other functions. Here's a braindump model, just modify (or restart, if you really don't like it) in subsequent comments:

• Analysis
  • show function to display the GUI
  • __str__ function which just prints the data (perhaps as JSON for better portability)
  • save function to save the graph as a file
• Blocks
  • lookup function which corresponds to lookup_block_type()
  • __str__ function which corresponds to --list option/print_block_types()
  • Reads a configuration file instead of blocks.py. The configuration file should have a group per hex code, a canonical name (from the wiki), a list of synonyms (i.e., obsolete names) for lookup, and links to the wiki for reference.