Fix display of residuals before displaying error message

The computed steady state was not updated.
Fix model_diagnostics.m for case where check1 contains NaN as second output

Also stops execution when steady state could not be computed as Jacobian at this incorrect steady state is wrong.
Merge pull request #464 from JohannesPfeifer/steady_display

Bug fixes for display of problems with steady state
Document that loglinear option is allowed for stoch_simul

Closes #431
Move check on variables types within 'shocks' block to the checking pass stage

Closes #448
Dynare++: prevent repeated assignment of a parameter/variable

This is not correctly handled by the evaluator.

Closes #415
Changed the syntax so that the difference between calling a member or a method is more explicit.

If a is a dynDate object:

a.format or a.format() are allowed because format is a method.

a.freq is allowed but a.freq() returns an error message because freq (same for time) is a member.