oaf/check

[nmaguiar]

Similar to ojob/check in objective with a set of checks.

Possible checks:

• Verify the use of variables already in scope (Move some scope functions to consts to avoid redefinition openaf#152)
• Verify checking of input arguments in functions

Could potentially use https://github.com/OpenAF/openaf-opacks/tree/master/PEG for Javascript parsing.