held suites and reload: Don't reset tasks in final states to held in held suites.

Closes #1226 

This stops tasks in a held suite whose states are succeeded/failed from being reset to held on a reload.

Can be tested with the following suite by holding the suite once bar has failed and issuing a reload. On master this results in foo and bar being set to held. On this branch foo remains succeeded and bar remains failed.
```
[scheduling]
    initial cycle time = 2013010100
    [[dependencies]]
        [[[ 0 ]]]
            graph = "baz[T-24] => foo => bar => baz"
[runtime]
    [[bar,baz]]
        command scripting = false
    [[foo]]
        command scripting = true
```

I don't think this is quite correct.  It should be this:
```python
elif self.is_held and itask.state.is_currently("waiting"):
   itask.reset_state_held()
```
In a reload, ... (will finish this comment later...)