[pdd07] allow fill-column: 78 in parrot files [GH #1054]

pod, parrot and perl files should allow easy and correct reformatting
of pod sections, and it does not harm to optionally reformat overlong
parrot lines to 78 also.

pdd07 only state MUST NOT longer than 100 columns,
and only later SHOULD have this code with 100.
Change pdd07 to allow 78 also.