Copying a glob to a directory creates extra directory level

[ianthomas23]

Another discrepancy that has arisen from #1226 and related work.

cp("source/somedir/*", "target/")

creates a new directory target/somedir and places the files in that. According to command-line copy, the somedir should not be created and the files should be copied directly into target.

[martindurant]

This should be identical to the case that the source is a list of files.