RUBY-950 Change module over to full class for the CrossProcessMonitor
RUBY-950 Adding generalized hooks for Rack as groundwork for cross process monitoring
RUBY-950 Supporting end of configuration callback

Will be used by cross process to wire up once we've gotten SSC returned
RUBY-950 Subscription to general agent rack hooks via class
RUBY-950 Wiring up to rack for cross process monitoring
RUBY-950 Commenting and logging on middleware instance tracking
RUBY-950 Including request Content-Length in cross process payload if provided
RUBY-950 Write out metric for timing on cross process metric
RUBY-950 Refactoring to break out methods
RUBY-950 Fixing up requires to address multiverse failures
RUBY-950 Seconds, not millis. Again.
RUBY-950 Handling case for blank passed on cross process id
RUBY-950 Rescue around AgentHooks.notify events for safety
RUBY-950 Queue time should clamp to 0 when small and negative
RUBY-950 Safer installation on the agent hooks middleware
RUBY-950 Adding minor logging when we're wiring up cross process monitoring
RUBY-950 Chomp chomp chomp
RUBY-950 Look for CGI style content length headers
RUBY-950 Clearer syntax on subscribing to the rack call result format
RUBY-950 Constants for header keys we look up repeatedly