`./moosedocs.py check` should fail if white-listed parameter does not exist

[andrsd]

Rationale

This check will prevent the docs to get out of sync when for example people rename parameters.

Description

When people use this syntax in their markdown files:

!syntax parameters /Postprocessors/DifferencePostprocessor show=non-existent-parameter

running:

./moosedocs.py check

should fail.

Impact

Doco consistent with the code.

[aeslaughter]

This should fail during "./moosedocs.py build" already. The check command does nothing with the markdown, it only checks that markdown pages exist for the application syntax.

[andrsd]

I tried with build and it does not report any errors on my machine. My syntax is:

!syntax parameters /GlobalParams/GlobalSimParamAction heading=None hide=active inactive asdf

or

!syntax parameters /AuxKernels/MaterialRealAux heading-level=3 heading=None show=asdf variable block execute_on