Rework clone panel.

Restyle the clone-panel to make buttons look more button-like.
Don’t “SSH” button when there is not a user logged in.

This is an extension of PR #5725. This meets the suggestion from http://feedback.gitlab.com/forums/176466-general/suggestions/4968567-correct-url-to-pull-puplic-repos-anonymously-on-pr to only show the "HTTP" option when a user is not logged in.

I have also changed the styling a bit to make the button look more like buttons. I also removed the bold from the selected as it caused resizing of the buttons when the selection changed (due to font width bold vs normal).

This also changes the cursor over the clone URL field to the regular pointer rather than the bootstrap restricted which is applied for readonly fields. I couldn't capture that, as the OS doesn't have the functionality, but it does work.

Here are some captures of the new look.

### HTTP selected
![http-selected](https://f.cloud.github.com/assets/2117996/1670238/2d622768-5c90-11e3-88f9-083c8ca41126.png)

### SSH selected
![ssh-selected](https://f.cloud.github.com/assets/2117996/1670239/3067af78-5c90-11e3-895f-9e2b89875523.png)

### Public project with no user logged in
![no-ssh](https://f.cloud.github.com/assets/2117996/1670240/32d5f760-5c90-11e3-822b-5d9b340d0d60.png)

### Old HTTP selected
![old-http-selected](https://f.cloud.github.com/assets/2117996/1670241/3578a850-5c90-11e3-8cc9-1aa92f2c6aa1.png)

### Old SSH selected
![old-ssh-selected](https://f.cloud.github.com/assets/2117996/1670242/378d5e42-5c90-11e3-9525-d539177ae34f.png)

If you look at the old captures, you can see the size of the clone panel has changed slightly.