Fixed: Environment configuration in Jakefile templates

Previously the Jakefile template for the capp utility would emit a template where the "configuration" build environment parameter could have multiple values. At the head of the file, the configuration parameter could be an environment variable composed of ENV['CONFIG'], ENV['CONFIGURATION'] or ENV['c']. It would default to "Debug".

However, other locations in this file did not use the detected configuration, and only looked at ENV['CONFIGURATION'] for the environment variable.

This commit fixes this by using the detected configuration environment variable as the build environment.