We need engine here
Add spawned param so we know if we are running as a service
Check spawned param instead of service (service is not passed to spawned process)
Tell spawned serve that is is spawned
Update logging configuration
Add ability to have a callback in the bundle
Bump version
Version bump
Fix filter and add vary: Accept_Encoding to header

Filter was being performed before cleanup which was not right, and
Vary: Accept-Encoding is supposed to improve cache performance on some
proxy servers (according to PageSpeed).
Improve some comments and add lastModified value to bundle
Combine two nearly identical code blocks into a single function
Update to reponse

Define headers in just one place. Add Last-Modified header
Moved the conditional to a better spot
Changed location of where we count number of bundleParts are completed
Version bump