Check physical lines after tokenizing them.
Check physical lines after tokenizing them.

This will make it possible to treat physical lines in multiline
strings distinctly, e.g. for issue #224 and #242 (not addressed yet;
this is just a prerequisite).

Details:
- readline_check_physical() is gone: now we only need readline()
- but now setting self.indent_char in check_physical() comes too late,
  so move that side effect up to readline()
- add maybe_check_physical() to decide after every token if it's time
  to check physical lines and, if so, do it

reinout/pep8,fabioz/pep8,ABaldwinHunter/pep8-clone-classic,doismellburning/pep8,MeteorAdminz/pep8,jayvdb/pep8,pedros/pep8,asandyz/pep8,jayvdb/pep8,PyCQA/pep8,ABaldwinHunter/pep8,fabioz/pep8,codeclimate/pep8,reinout/pep8,zevnux/pep8,pandeesh/pep8,ojengwa/pep8