Rewrite the HappyProcessStart to more correctly deal with environment
Rewrite the HappyProcessStart to more correctly deal with environment

The existing implementation of HappyProcessStart had a number of bugs
in cases where the environment variables contained "complicated"
values, i.e. values containing spaces, quotes, backslashes,
semicolons, etc. This implementation improves on the previous
implementation in that the environment variables can now contain the
above characters and will be properly escaped.

openweave/happy,openweave/happy