List alternative versions of halo catalogs when there is no match

[aphearin]

Suppose the user knows that there is a bolshoi catalog at z ~ 0.35 stored in cache, but cannot remember the version_name:

>>> halocat = CachedHaloCatalog(simname='bolshoi', redshift=0.35)

In the current code, if there is no match, there will be an error message printing out the list of available catalogs with default_version_name, but none with the alternate version name, even if the redshift is an exact match to the alternate version name.