conn.py performance improvements, make examples work, add another example

[wizzat]

The change consists of:

• Adding load_example.py, which shows large message behavior.
• Updating example.py to actually compile and run.
• Adding ErrorString handling so that human readable error messages are easier to get to.
• Refactoring conn.py to use a common init/reinit pattern.
• Refactoring conn.py to use ''.join() instead of str += str (~5-10% performance increase on my limited testing)

[wizzat]

This pull request is against my master, which is silly. I'm closing this pull request and will reopen it against a feature branch.