Web project merge

Updated gem for use in all projects
Merged duplicated execption_handling.rb  code from existing project, ported tests to RR, added new API, and bumped major revision.
The constant that this variable came from (e.g. `EVENTMACHINE_EXCEPTION_HANDLING`) was overloaded to accept `true` or `:Synchrony`.  I broke this into two explicit settings (class variables).  I expect some search&replace when upgrading projects to use this new gem version.  I added the true|false restriction to make sure the old usage threw an explicit error.