Properly set fgout q_out_vars to default

[rjleveque]

Should be [h,hu,hv,eta] as in old versions, but now qmap['eta'] varies depending on equations being solved (e.g. geoclaw-bouss or dclaw).

[mandli]

I am not sure I am understanding why qmap would not be defined and would require a try-except block. If anything maybe we are expecting an integer in the dictionary?

[rjleveque]

qmap should always be defined but the user might pass in a custom qmap that does not contain eta. Probably not, but I was being extra cautious.

The main change is that qmap['eta'] should be used rather than hardwired to 4.

[mandli]

Maybe just checking the dictionary for the key eta and throw an exception then?

[rjleveque]

Maybe just checking the dictionary for the key eta and throw an exception then?

Good idea to check for key, I changed it.