Added doc target.
Fixed errors that prefented doc from running.
Removed unused modules.

Not exactly a documentation change, but makes documentation make more
sense if unused modules are removed.
Cleaned up doc output for pre_data.

Added some specs to some unspeced functions and removed dividers that
were pointlessly cluttering the output.
Shored up docs for the entity layer app.
doc cleanup in the pre_comms app.
Removed comm layer from a deps list.

Deps are those that need to be retreived, which makes rebar get
confused when it can't retreive it.
Merge pull request #39 from SkewedAspect/bug-mw-doc-creation

Bug mw doc creation