Extend the Module.ExternalData test to cover a DATA{} reference whose
name contains a space. Skip the case when the native build tool does
not support spaces.
Use a trailing slash to reference a directory. Require that a list
of associated files be specified to select from within the directory.
One may simply use DATA{Dir/,REGEX:.*} to reference all files but
get a directory passed on the command line.
Add a Module.ExternalData test to verify data retrieval and test
argument DATA{} references.
Add a RunCMake.ExternalData test to verify error handling and automatic
transformation of a raw data to a content link and staged object.
Brad King