Insufficient documentation for COMPUTE_TREELINE and JULY_TAVG_SUPPLIED about vic

[tbohn]

I have updated the online documentation as follows:

1. expanded the description of these options and parameter so that the conditions under which July average air temperature must be supplied are explicitly mentioned (earlier, the reader had to infer the conditions from the description)
2. added cross links among the definitions of all three of these terms.

The following web pages were updated:
Documentation/GlobalParam.shtml
Documentation/SoilParam.shtml

[bartnijssen]

Actually - this should be marked as a bug, because one of the effects is that the model state is not restored as expected under certain conditions, resulting in non-sensical results, without a clear warning.

Expected behavior:
The model should abort with a descriptive error message if COMPUTE_TREELINE is turned on and JULY_TAVG_SUPPLIED is not supplied (or cannot be calculated, but I suggest that JULY_TAVG_SUPPLIED needs to be true to simplify things).

I think the behavior as implemented by Ted is sufficient for 4.1.2.j, but we should have the model fail for 4.2.

[jhamman]

I have issued a pull requests that requires JULY_TAVG_SUPPLIED=TRUE when COMPUTE_TREELINE=TRUE. If this condition is not met, a descriptive abort message is given.

[bartnijssen]

Merged pull request