Cleanup InputLocation

[heubi95]

• self._location = errors.InputLocation(cid_path, hasCell=True) call advanceLine() for every row and advanceCell() for every column while parsing
• InputLocation:
  • delete __str__
  • rename __unicode__ to __str__
  • replace the deprecated __cmp__ function with __eq__ and __lt__

[roskakori]

Hints on implementing __eg__ and __lt__: http://regebro.wordpress.com/2010/12/13/python-implementing-rich-comparison-the-correct-way/

Rough implementation of InputLocation.__lt__():

    def __lt__(self, other):
        return (self.filePath < other.filePath) \
            and (self.line < other.line) \
            and (not self._hasColumn or (self.column < other.column)) \
            and (not self._hasCell or (self.cell < other.cell)) \
            and (not self._hasSheet or (self.sheet < other.sheet))