Updating 'headless' dep. version
Fixing string representation of agentsets
Correcting the breed and kind returned by `turtles-on` (fixes #88)

The most obvious implication of the old behavior was that the result of
`turtles-on` would throw an exception when converted to a string
Revert "use webjars-locator"

This reverts commit 9659ff372067c273ec884729ac289c927ab5940e.
Disabling dependency permissioning in these pastures...
Creating a handy, dandy 'jsengine' package
Introducing Benchmarker 1.0
Adding version number of JS engine to benchmark

It just makes sense to include version numbers of external libraries
into the benchmarks, since changing version numbers can change speed.
Minor package-pushing (refactoring)
Pumping up the private sector
Adding SpiderMonkey support