rationalize use of suite stdout, stderr, and the log

[hjoliver]

Currently this is not very well organized. You really have to look at all three files to see what's going on if an error occurs.

Perhaps we should only use the log: it automatically time-stamps entries, it handles multiple threads nicely, and the amount of logging done is configurable.

[hjoliver]

Also, no need to preface an exception message with "ERROR", except at the outermost level.

[matthewrmshin]

We agree with this proposal.

[matthewrmshin]

We should also review what should go into the log in normal mode. There are lots of items which are probably not too useful and/or just repeating what would go into the suite runtime database file.

[hjoliver]

We didn't really come to a consensus on exactly what should be in each of these files.

We did agree that, at the least, we should review and document exactly what goes where. (including other files should as the job activity log).

[matthewrmshin]

Since #2437, a running suite should no longer write to the out file.