Revert "Merge branch 'expand_envs_config' of github.com:ecnahc515/heka into ecnahc515-expand_envs_config"

This reverts commit cbe13198f8082ead1005650512bfaef5695254d9, reversing
changes made to 663e613c9cf7a0f0e3752bade312abba86af3f7f.
Merge pull request #1063 from ecnahc515/revert_env_conf

Revert "Merge branch 'expand_envs_config' of github.com:ecnahc515/heka into ecnahc515-expand_envs_config"
Revert "Revert "Merge branch 'expand_envs_config' of github.com:ecnahc515/heka into ecnahc515-expand_envs_config""

This reverts commit 28a518b9f61504bf986348ac7210f9defb87774e.
Reimplement environmental variable support in config
Fix the serialize benchmark and remove variables from global scope
Merge pull request #1065 from mozilla-services/lua-test-cleanup

Fix the serialize benchmark and remove variables from global scope
Better comments. Remove commented code.
Merge pull request #1064 from ecnahc515/expand_env2

Second attempt at expanding env variables in config