Merge pull request #2 from dmilstein/master

Add support for scripts which reply privately to the sender of a hutbot command
Add MessageLogger and ResponseLogger.

These can invoke a log script for each message _and_ response and ignore
the output of the script, allowing for logging or processing that
includes Hutbot's responses without danger of feedback.
Call other scripts with a HUTBOT_EVENT variable.
Start adding some tests.
Automatically reconnect when the bot quits.

This is a rough approximation for a forced disconnect (being kicked/ping
timeouts/etc.) as the bot should never issue a QUIT on its own.
Add rate-limiting for IRC responses.
Add a disconnect before attempting to reconnect.
Fix re-joining by actually checking for bot quit.

We were comparing the connection's nick against the bot name (basically
always the same) instead of the nick of the quitter.
Update for upstream changes to go-ircevent.
Execute scripts concurrently with a process pool.
Fix private messages bug.

Target was not getting passed through correctly, so private messages
were going to the channel rather than the individual.
Fix a bug with error reporting.

Use the correct executable name when reporting a failed command (this is
another closure variable fix).
Capture stderr, report it on failed commands.