Add metrics sessions, don't use global event emitter for reporting.
Delete emit.js.
Merge branch 'metrics' into develop
Fix minor logging.
Set the outgoing connection limit to Infinity

The default in Node 0.10 is 5 per host:port, which is a ridiculous
limitation for a proxy.
Updated readme.
Merge branch 'readme' into develop
Fix metrics reporting.
Merge branch 'metrics' into develop
Added url expander plugin.
Removed 'follow-redirect' module.
Added url expander tests and fixed incorrect request handling in the
plugin.