Alias stringlength url parameter and maxstrlen

[DennisHeimbigner]

re: esupport AVS-567793

Some parameters like stringlength actually affect a dimension
named maxStrlen. So, add some aliasing so maxstrlen can be
specified as a parameter and as an alias for stringlength.

The affected parameters (case insensitive):
stringlength has alias maxstrlen
stringlength_ has alias maxstrlen_

Also:

1. added a test case in ncdap_test/testurl.sh
2. added note to documentation

[WardF]

Still need to diagnose the issue, but I am seeing a lot of coredumps when I try to run tests on this branch. I'd suggest it's relatively low priority to get this in, but this is why it's currently languishing. I'll see if I can get a cdash output submitted and, if so, will post a link to the verbose results.

[WardF]

Output is here: http://cdash.unidata.ucar.edu/viewTest.php?onlyfailed&buildid=2491

It is not particularly useful; the failures stem from failed diff comparisons. The underlying cause for the diff failure is a core dump/crash when the underlying script invokes one of the utilities (I haven't tracked it down yet, just trying to get this info written down).

[DennisHeimbigner]

Last travis output seems to indicate a memory allocation error.

[DennisHeimbigner]

There was some kind of duplicated code problem that was causing all sorts of
problems. Anyway, sorted it out and merged master.

[WardF]

Excellent, thanks Dennis!