re: Issue https://github.com/Unidata/netcdf-c/issues/2704
The issue reported problems accessing e.g. opendap.earthdata.nasa.gov,
which uses the authentication mechanisms of urs.earthdata.nasa.gov.
The file *docs/auth.md* describes how to setup the proper authorization
mechanisms for earthdata, but there turned out to be some bugs
in the code that prevented this from working.
## Primary Changes
* Add some clarification text to *auth.md*.
* Fix the process for loading and merging *.ncrc* and *.dodsrc* file to conform to documentation.
* Fix *NC_s3urlrebuild* so that non-S3 urls are passed through unchanged.
* Fix a bug in the .rc test *test_rcmerge.sh*.
12ec5711d7
