Fix spelling of 'necessary' in comments and docs

lib/modules/Calendar.pmod/Event.pmod

lib/modules/Calendar.pmod/TimeRanges.pmod

lib/modules/Standards.pmod/ID3.pmod

lib/modules/String.pmod/Elite.pmod

src/modules/Image/image.c

src/modules/MIME/mime.c

src/peep.in