All of the removed `from __future__ import` were needed in older
versions of Python (mostly 2.5.x and below) but later became mandatory
in most versions of Python 3 hence are not necessary anymore.
More specifically, according to __future__.py[1]:
- unicode_literals is part of Python since versions 2.6.0 and 3.0.0;
- print_function is part of Python since versions 2.6.0 and 3.0.0;
- absolute_import is part of Python since versions 2.5.0 and 3.0.0;
- division is part of Python since versions 2.2.0 and 3.0.0;
Get rid of those unnecessary imports to slightly clean up the codebase.
[1] https://github.com/python/cpython/blob/master/Lib/__future__.py
(do-over of c85984f105106ff0a7e3b387d680e0f2f5884d55)
If a block contains a callback of the form
self.block_id.param = $param
the generators subst routine produced
self.block_id.self.param = self.param
due to a faulty splitting of the expression in expr_utils.py.
This should fix this problem by not tokenizing "VAR0.VAR1".
