Refactor MANIFEST.in by using global-exclude
Update library versions
Improve log messages
Update comments
Add clean task for make
Increase threshold for Lazy Load
Remove Ruby dependency

I was intending to remove Node.js too, but
it turns out that it is not an easy task. Python-CoffeeScript
depends on PyExecJS which depends on other runtimes including
PyV8, Node.js, Apple JavaScriptCore, Mozilla SpyderMonkey, and
Microsoft Windows Script Host (JScript) among which PyV8 is the
only Python runtime (even though it is a just wrapper).
However I cannot install PyV8 with 'pip install pyv8' since
it always stalls whenever it tries to checkout the revision
205936 of something called icu. I feel it is too early to
get rid of Node.js right now.
Fix bug where MAIL_TOADDRS are not parsed properly
Fix parsing errors

Also increase logging level for parsing failure. Admins will receive
emails.
Improve robustness when scaling heroku

* Catch HTTPError and report to admin because it is most likely
  a serious problem
* Check if already scaled before scaling by saving number of processes
  in the DB
Improve worker

Catch exceptions at runworker(), not at browser methods

Add BrowserException

Remove default exc handler from rq.Worker

Fix detached instance bug

Fix worker running infinitely
Add CHANGES