Merge branch 'filter-private-token-param' into 'master'

Filter private_token and password_confirmation params from logs.

Closes #1770.

```
Started GET "/profile?private_token=[FILTERED]" for 127.0.0.1 at 2015-02-06 22:54:03 +0100
Processing by ProfilesController#show as HTML
  Parameters: {"private_token"=>"[FILTERED]"}
```

See merge request !1483