Reduce volume of Travis build output

Hundreds of lines of build output passed through Travis JS parsing bring
my browser (at least) to its knees - little of it is interesting or even
relevant, keeping the last 40 lines of stdout for most make targets is
plenty (we keep all of stderr).
Test some management commands

This is far from complete, but may catch some regressions
Require Jinja2 < 2.7 for Python 2.5

Jinja2 is a requirement of Sphinx (used to build documentation), but the
latest (2.7) version requires Python 2.6; allow build to succeed by
installing older 2.6 version before processing requirements
Propagate failure status through |tail

This restores proper failure detection broken in earlier commit titled
"Reduce volume of Travis build output"
Always notify on failure
Fix background runserver for 1.3<=Django<1.3.7

For early 1.3 Django releases, backgrounded manage.py runserver without
--noreload gets an unhandled exception due to loader thread calling
ensure_echo_on which gets "Inappropriate ioctl for device." Thanks Jiaaro:
http://stackoverflow.com/questions/6369054/run-python-manage-py#6374707
Typos in 2.5.0 release notes
Add note about Jinja2 and Python 2.5