add unit tests for syntax errors
add unit tests for deprecated python usage
add unit tests and fix whitespace errors and warnings
add unit tests and fix blank line errors and warnings
add unit tests for import errors
add unit tests and fix statement errors
add unit tests and fix redundant backslashes between brackets
add unit tests and fix lexical indentation for python3

These are the pep8 tests that break python3,
such as mixing tabs and spaces for indentation.

I ignored all the pep8 tests that seemed only stylistic,
such as "visual" indentation.

http://docs.python.org/3.3/reference/lexical_analysis.html
exceptions are now compatible with both python 2.5 and 3.3

The syntax for capturing exceptions changed in python 3, but
we need to continue supporting python 2.5 syntax since many
people use tito on RHEL 5, which has python 2.5.

http://docs.python.org/dev/howto/pyporting.html#capturing-the-currently-raised-exception
add modules compat lib to support both python 2 and 3

Tito uses two modules that have changed significantly between
python 2 and 3:

* commands module merged into subprocess module
* ConfigParser module renamed as configparser
use print function, not statement, for python3 compatibility