Merge pull request #1 from sthadka/master

Add option to push error data to collector
Use statman counters for tracking errors

Keys of the format {<<"/some/url">>, {error, {Type, Message}}}
will be send to newrelic as errors.
Update README for error counters
Fix README, missing back tick
Merge pull request #2 from chrisavl/master

Use statman counters to report errors
Merge remote-tracking branch 'upstream/master'