Sanitize the Python 2 check.

This broke for me on a project that has a module called 'builtins'.
Let's just do a proper check using the normal `sys.version_info` API.
Merge pull request #20 from nvie/master

Sanitize the Python 2 check
Remove Python 2.5 from Travis configuration

It is no longer supported by Travis CI.

https://about.travis-ci.org/blog/2013-11-18-upcoming-build-environment-updates/
Merge pull request #21 from myint/travis

Remove Python 2.5 from Travis configuration
Display caret correctly

Previously, pyflakes had two problem when displaying the caret. The
first problem was it did not display tabs correctly. This is related to
scrooloose/syntastic#924.

The second problem was the caret was off by one (compared to what python
command-line displayed).
Generalize test to work non-Python 3.3
Add failing doctest syntax test
Fix crash when no "offset" in doctest syntax error
Add Python 3.4 to tox.ini
Merge pull request #16 from myint/master
Pass tests on Python 3.4 beta
Merge pull request #23 from myint/caret
Merge pull request #19 from laurentb/doctest-fix
Update changelog.
Credit the original author of pyflakes
Merge pull request #24 from bitglue/master

Credit the original author of pyflakes