Revise footer to be less verbose and more like 1.2.x

- Don't show administrator email on login page -- it is useful for users hitting login issues but can disclose the address outside the organization - can move to always ON based on feedback.
- Show copyright years independent of show_version given that they currently are from 0 to today's year, so no disclosure of versioning anyway.
- User copyright message shows up after MantisBT copyright and before contact administrator message.
- Use much brief message for contacting administrator.  Remove usage of the word "us".

Here is a screenshot with show version ON and user logged in:
![screen shot 2014-01-12 at 9 55 00 pm](https://f.cloud.github.com/assets/6446/1898295/9f35be94-7c17-11e3-9f44-83762d1ac335.png)