Reorder package.json dependencies alphabetically

This is what happens when you do 'npm install module --save', so it
makes sense to do this in a separate commit so future commits don't have
so much noise in them.
Upgrade express to v3.17.5

This is the latest version in the 3.x series and contains deprecation
warnings that should be helpful when upgrading to the 4.x series.

The change from ~ to ^ in package.json is because a newer version of npm
has been used to install this module. See
http://fredkschott.com/post/2014/02/npm-no-longer-defaults-to-tildes/
for more details.
Update dev dependencies