Multiple CSS fixes
    
    - Merge the two fields we had for textarea and make them use monospace
      fonts at a size of 120%
    - Ensure the links to the user and row number remain readable when hovering
      over
    - Make the lineNum use monospace font at a size of 120%
    - Give some space to the break row inserted near the textarea when doing
      online editing
    - Use monospace fonts for comment and issue_content at a size of 120%
    
    Fixes https://pagure.io/pagure/issue/427