Getting a `resize-world` language test passing
upgrade to latest headless branch stuff

including api/core package split
track latest NetLogo changes
Merge branch 'master' into resize-world-test-fix

Conflicts:
	src/test/scala/TortoiseFixture.scala
Fixing some language tests by getting `stop` working correctly

calling a Tortoise procedure is now expected to happen through a
global Call function, instead of directly.  the purpose of Call
is to catch StopInterrupt (thrown by `stop`).  `askAgent` also
now catches StopInterrupt.
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