Update most dependencies.

Updated most dependencies, using the listing from `npm outdated`. Tests still run, so I guess it works.

I also updated lodash, but that broke the tests. Leaving it out for now. (Current is 0.9.2, latest is 2.4.1)

grunt-legacy-util should update its async (0.9.0), underscore.string (2.3.3) and lodash packages.