Legacy support

@drsnyder 
https://wikia-inc.atlassian.net/browse/PLATFORM-380
Support for the legacy thumbnailer interface. The old thumbnailer supported thumbnail names like [130px-0,374,6,337-Shingo_Seabass2.jpg](http://images.wikia.com/proevolutionsoccer/pt/images/thumb/a/a2/Shingo_Seabass2.jpg/130px-0,374,6,337-Shingo_Seabass2.jpg). We chose not to support the extra comma-separated params, so the following URLs are equivalent to us:

http://localhost:8080/proevolutionsoccer/pt/images/thumb/a/a2/Shingo_Seabass2.jpg/130px-0,374,6,337-Shingo_Seabass2.jpg
http://localhost:8080/proevolutionsoccer/pt/images/thumb/a/a2/Shingo_Seabass2.jpg/130px-Shingo_Seabass2.jpg

The images aren't exactly the same, but we should be OK with that.

```parse-request-log``` in the ```user``` namespace prints urls from a log from the legacy thumbnailer that we cannot parse. I ran this against a sample of images collected over a 1 hour period on our production thumbnailer (44.8k URLs), and there were less than 50 that we couldn't match. These errors were due to either a poorly, probably hand-generated URL from a user, or from double slashes in the URL. We should be OK with those failing as well IMO.

TODO:
- [ ] log a legacy URL that results in a 404.
minor: Move the revision logic out into a separate function.