Pushed duration service argument through C++ side.
Added tests for scheduler.

These test pass meaning the duration code runs. It still may not be correct though.
Updated and tested FIFO executor. Removed MDP depedency from base executor.

This is now ready for a full release without the MDP parts.
Restored missing code.
Merge pull request #93 from hawesie/hydro-release

Moving recent changes to release.