policycoreutils/sandbox: improve compatibility with Python 3

- gettext.install() only takes optional "unicode" keyword argument in
  Python 2, and its default value is "False". This keyword argument
  doesn't exist in Python 3
- __builtin__ module has been renamed to "builtins" in Python 3
- raw_input() has been renamed to input() in Python 3
- specify octal literals in form compatible with both Python 2 and 3
- migrate from commands to subprocess
- replace print statement with print function
- use reserved word `as` in try-except
- replace deprecated assert_() method with assertTrue() in unit tests

Signed-off-by: Michal Srb <msrb@redhat.com>
3 files changed