[bash manual] suggestions, fixes, license

[Aaron S. Hawley]

- added material to first section to read clearer
- small fixes and suggestions
  - updated independent-ports
- changed @ifinfo to @ifnottex
- implemented suggestions made by karl berry to the bash bug list[1]:
  - including using the @copying and @insertcopying
  - including using the GNU FDL
    - includes "fdl.texi" available at
      http://www.gnu.org/licenses/fdl.texi

1. http://mail.gnu.org/archive/html/bug-bash/2003-02/msg00021.html

let me know what does and doesn't work out.
/a