Simplify goal urls

[Michael Nelson]

Current goal urls look like:

/goals/michael/wants-to/speak-german-with-the-proficiency-of-a-10-year-old/

The decision for such urls was based on readable (and search-able) urls, but the same benefit could be achieved with urls like:

/goals/michael-wants-to-speak-german-with-the-proficiency-of-a-10-year-old/32/

where the only identifying data is the primary key (32). Any other urls where the text was different (/goals/foo-bar/32/) should redirect to the url with the correct text. The url without the text (/goals/32/) should work without redirection (useful for api support).