Update FatesAllVars to include more expansive set of variables for fates regression tests

[glemieux]

In addressing issue #549, @jkshuman asked the relevant question as to why we hadn't noticed that fuel_moisture_nfsc was uninitialized in any of our previous tests. Looking through the standard regression tests it appears that it's not set in any of the test definitions, particularly in FatesAllVars/usr_nl_clm. Chatting with @ckoven, he suggested we may need to review and expand the set of variables for the tests.

The one question I had is what is the effect of hist_empty_htapes = .true. on the fates history variables? My initial assumption was that this turns off all default input including all the fates history variables that are 'active' by default.

[glemieux]

Closing. We should add a note to the fates user's guide to add the use of the FindInactive tool to the workflow whenever a new history variable is added to the list.