Change the sourceMappingURL pragma to use the new //# syntax, update packages

All browsers that implemented support for source maps except for Chrome (i.e. Firefox & Safari) did it in the same versions that got the updated `//# sourceMappingURL` pragma syntax (Firefox in version 24, Safari in 6.1/7). Chrome has updated the pragma in version 29 which has already been released so it's time to switch.

This pull request also updates node dependencies of the project.