Check if it's a folder to prevente "open_basedir restriction"

The code list folders and files listed in "modules" folder which generate a warning:
Warning: is_file(): open_basedir restriction in effect. File(./modules/index.html/module.php) is not within the allowed path(s): ([...]) in [...]/serposcope/inc/common.php on line 75
The test prevente file listing.
Add type to fields to apply Twitter BS style.

without the type TBS cannot apply the CSS rounded style.
Wrap "Add" button with paragraph tag.
Merge pull request #2 from alxblog/master

Fix open_basedir warning
Minor modification