Multiple time-averaged files

[arango]

There is a bug when creating multiple time-averaged NetCDF file when ndefAVG=nAVG and ndefDIG=nDIA (that is, one output record per file). Initially, it creates an empty file. In these cases, the file creation needs to be delayed until the time-average interval is completed.

[arango]

I also disallowed the creation of multiple history NetCDF during any of the 4DVAR algorithms. Otherwise, the basic state will not processed correctly. I also corrected the logic of creating tangent and representer history files. We need to have the same logic as in the nonlinear model.

[arango]

Fixed unmatched parenthesis in output.F when the term diagnostics are activated.