The problem was that for opendap, it is possible to use keywords
as identifiers
when there is no ambiguity. However, the DAP2
parser lost the case of the identifier used the lower case version.
Fix is to use the actual text of the symbol when it is used as an identifier.
Also added a test case for this (kwcase.*).
Additionally cleaned up some misc. dap2 testing problems.
1. ncdap_test/tst_ncdap3.sh was using an empty test set.
restored the testing of datasets.
2. as a consequence of #1, some tests needed to be updated with minor
tweeks.
3. fix dapmerge to handle multiple DODS_EXTRAS attributes.
4. modify buildattribute to suppress nul characters and terminate
the name at the first nul.
5. clean up various test scripts to remove residual, unused
references to obsolete netcdf-4 translation.
6. export e.g. NCDUMP from test_common.in so that non-top-level
shell scripts can access it.
