Mentioned - but not included - new YAML parser psych in the Gemfile

Psych is new - and default in Ruby. Syck ( default parser on Heroku ) is old -
and unmaintained

But until Ruby-1.9.2p180, psych could not merge nodes. We are on p136
Syck works as expected

Questions:
  1. Upgrade to Ruby p180  ?
  2. Upgrade to psych - or stick with syck ?
Force syck as YAML parser in all modes - especially deelopment
DRY'ed up onclick.yml and in the process corrected errant behaviour