Improve handling of trailing slash

As per the current spec trailing slashes are ignored for the selection of root
resources and resource methods.

This is odd, because it gives effectively two names to the HTTP-resources made
available but it also has a significant practical disadvantage: A resource
method that generates relative links has to have the UriInfo injected and check
for the presence/absence of trailing slash and either adapt the relative links
or send a redirect. It would be good if implementations would free applications
from this burden.

See also: mail-thread from 2009-01-06 on users@jsr311.dev.java.net "trailing slash"
#### Environment
Operating System: All
Platform: All
#### Affected Versions
[2.1]