hgwebdir: export collections of repos
now you can use [collections] section in hgweb.config to export entire
tree of repos.
adding aadding baNONEXISTENT: No such file or directoryaba: No such file or directoryNONEXISTENT: No such file or directorybaNONEXISTENT: No such file in rev 9e1684505872ab