Bug fixes:
----------

* fix relative paths for croot argument to CLI; test  #2335
* fix several issues with zip_keys  #2340
* fix output build number never applying  #2340
* fix ensure_matching_hashes for strong/weak run_exports  #2340
* fix indexing of channels, especially before testing packages  #2341
* copy wheels and unextractable files (.sh) into the workdir with their original, un-hashed filename, for simplicity in working with them.  #2343
* avoid attempting to overwrite existing files in the source cache  #2343
* avoid unsatisfiable requirement errors by adding .* to specs that lack .* or >/</>=/<=  #2344