Logical folders allow for logical URI resolvers to collect items from different sources and concatenate the results. Currently only PATH:/// uses this feature.

[jurgenvinju]

• added ILogicalSourceLocationResolver.resolveList
• uses the above in URIResolverRegistry::listEntries
• this new feature is not related to the mvn:// scheme, since the mvn scheme is not
  about collecting information from different folders or files.

• PATH:/// finally lists all of the present files and folders reachable from the unix/windows search PATH
• requires some more interactive testing, especially w.r.t. auto-completing logical and physical locations, with and without empty authorities, and with and without present authorities as alternative to ""