Merge branch 'email_in_gravatar_urls' into 'master'

allow passing user's email address in custom Gravatar urls

Some custom avatar systems use the user's email address rather than its hash. This merge request will allow the administrator to configure gitlab-ce to use the user's email address gravatar.plain_url and  gravatar.ssl_url in the config file like this:

```
gravatar:
    enabled: true
    plain_url: "http://company.com/avatar/?mail=%{email}&size=%{size}"
    ssl_url: "https://company.com/avatar/?mail=%{email}&size=%{size}"
```

It's a only a 2 word patch.

app/helpers/application_helper.rb

@@ -75,7 +75,7 @@ module ApplicationHelper
     else
       gravatar_url = request.ssl? || gitlab_config.https ? Gitlab.config.gravatar.ssl_url : Gitlab.config.gravatar.plain_url
       user_email.strip!
-      sprintf gravatar_url, hash: Digest::MD5.hexdigest(user_email.downcase), size: size
+      sprintf gravatar_url, hash: Digest::MD5.hexdigest(user_email.downcase), size: size, email: user_email
     end
   end
 

config/gitlab.yml.example

@@ -117,6 +117,7 @@ production: &base
   ## Gravatar
   gravatar:
     enabled: true                 # Use user avatar image from Gravatar.com (default: true)
+    # gravatar urls: possible placeholders: %{hash} %{size} %{email}
     # plain_url: "http://..."     # default: http://www.gravatar.com/avatar/%{hash}?s=%{size}&d=mm
     # ssl_url:   "https://..."    # default: https://secure.gravatar.com/avatar/%{hash}?s=%{size}&d=mm