For #946: proxy portlet passes group information

NOTE: By default it doesn't look like a user is necessarily in a group. The group id I get by default is 88 and the group name is 88 as well, but they don't show in the Liferay UI.

Also:

- unify full portlet Liferay header code with proxy portlet code
- fix roles header name
- small refactoring
Proxy portlet: input field width