feat($resource): collapse empty suffix parameters correctly

Previously only repeated `/` delimiters were collapsed into a
single `/`.  Now, the sequence `/.` at the end of the template, i.e.
only followed by a sequence of word characters, is collapsed into a single
`.`. This makes it easier to support suffixes on resource URLs.
For example, given a resource template of `/some/path/:id.:format`, if
the `:id` is `""` but format `"json"` then the URL is now
`/some/path.json`, rather than `/some/path/.json`.

BREAKING CHANGE: A `/` followed by a `.`, in the last segment of the
URL template is now collapsed into a single `.` delimiter. For example:
`users/.json` will become `users.json`. If your server relied upon this
sequence then it will no longer work. In this case you can now escape the
`/.` sequence with `/\.`