Wrap presenter notes from pdfcomments

Created originally on Bitbucket by logstarx (logstar Z)

Changesets for this Pull Request have not been imported, because it had been already declined on Bitbucket. Marked as closed by the import user.

Attempt on Issue #27: enhancing note support -- issue #20: autowrapping notes.

Simply call textwrap.fill() to wrap the text in 70 characters each line.

Works for MacOS 10.12.6 . Tested with empty, short (proposal characters), and long (4715 characters) single line pdfcomments. All rendered correctly.

Documentation of textwrap.fill():

https://docs.python.org/2/library/textwrap.html#textwrap.fill

textwrap.fill(text[, width[, ...]]):

Wraps the single paragraph in text, and returns a single string containing the wrapped paragraph.