improve a link in the Transition Guide
document effects of agent death
bring network extension up to date with recent LinkManager changes
fix #323 (`myself` fails with exception)
Merge remote-tracking branch 'origin/5.0.x'
don't mess with java.ext.dirs unless launching GUI

why?  well, we mess with it for JOGL's sake, since we don't want to
pick up a JOGL installation other than the one that comes with
NetLogo.  but if we're not running the GUI, we're not using JOGL.
and messing with java.ext.dirs may have unwanted side effects.
in particular, I discovered today that on JDK 8, Nashorn doesn't
work if java.ext.dirs is empty, because nashorn.jar is in
jre/lib/ext/nashorn.jar under $JAVA_HOME.
upgrade issues script to latest Dispatch, etc.
relocate plot.PlotAction to api package
cut dependency of prim.plot on plot package
merge prim.plot into prim.etc

since it doesn't have a dependency on org.nlogo.plot anymore,
there's no further need to have a separate package
splitting compiler into compiler and parse

a package is born!  this will facilitate cutting the front end's
dependencies on the engine, since we don't want Tortoise depending
on our JVM back end code
move more front end code to parse package
split ParserInterface off from CompilerInterface
rename CompilerServices -> ParserServices
cleanup: avoid importing parse._
rename packages: compiler -> compile, generator -> generate
graffle oops
Merge remote-tracking branch 'origin/master' into core

Conflicts:
	bin/issues.scala
	dist/depend.graffle
	docs/dictionary.html
	docs/transition.html
	extensions/network
	headless/resources/system/tokens.txt
	headless/src/main/org/nlogo/api/AggregateManagerInterface.scala
	headless/src/main/org/nlogo/api/HubNetWorkspaceInterface.scala
	headless/src/main/org/nlogo/compile/Optimizer.scala
	headless/src/main/org/nlogo/compiler/CompilerMain.scala
	headless/src/main/org/nlogo/headless/HeadlessWorkspace.scala
	headless/src/main/org/nlogo/hubnet/protocol/ClientInterface.scala
	headless/src/main/org/nlogo/nvm/CompilerInterface.scala
	headless/src/main/org/nlogo/nvm/DefaultCompilerServices.scala
	headless/src/main/org/nlogo/parse/AutoConverter1.scala
	headless/src/main/org/nlogo/parse/AutoConverter2.scala
	headless/src/main/org/nlogo/parse/LiteralParser.scala
	headless/src/main/org/nlogo/parse/Parser.scala
	headless/src/main/org/nlogo/sdm/AggregateManagerLite.scala
	headless/src/main/org/nlogo/sdm/Loader.scala
	headless/src/main/org/nlogo/sdm/Translator.scala
	headless/src/main/org/nlogo/workspace/AbstractWorkspace.java
	headless/src/test/org/nlogo/compile/AgentTypeCheckerTests.scala
	headless/src/test/org/nlogo/compile/AssemblerTests.scala
	headless/src/test/org/nlogo/compile/ConstantFolderTests.scala
	headless/src/test/org/nlogo/compile/OptimizerTests.scala
	headless/src/test/org/nlogo/parse/AutoConverter1Tests.scala
	headless/src/test/org/nlogo/parse/AutoConverter2Tests.scala
	headless/src/test/org/nlogo/parse/ExpressionParserTests.scala
	headless/src/test/org/nlogo/parse/IdentifierParserTests.scala
	headless/src/test/org/nlogo/parse/LetScoperTests.scala
	headless/src/test/org/nlogo/parse/LiteralParserTests.scala
	headless/src/test/org/nlogo/parse/StructureParserTests.scala
	headless/src/test/org/nlogo/sdm/LoaderTests.scala
	headless/src/test/org/nlogo/sdm/ModelTests.scala
	headless/src/test/org/nlogo/workspace/DummyAbstractWorkspace.scala
	project/Depend.scala
	src/main/org/nlogo/app/App.scala
	src/main/org/nlogo/app/WidgetPanel.java
	src/main/org/nlogo/hubnet/client/App.scala
	src/main/org/nlogo/hubnet/client/ClientApp.scala
	src/main/org/nlogo/hubnet/client/ClientGUI.scala
	src/main/org/nlogo/hubnet/client/ClientPanel.scala
	src/main/org/nlogo/hubnet/client/EditorFactory.scala
	src/main/org/nlogo/hubnet/client/RoboClientPanel.scala
	src/main/org/nlogo/hubnet/server/gui/GUIHubNetManager.scala
	src/main/org/nlogo/lab/gui/ProgressDialog.scala
	src/main/org/nlogo/lab/gui/ProtocolEditable.scala
	src/main/org/nlogo/lite/LiteEditorFactory.scala
	src/main/org/nlogo/lite/LiteWorkspace.scala
	src/main/org/nlogo/sdm/gui/AggregateModelEditor.java
	src/main/org/nlogo/sdm/gui/GUIAggregateManager.scala
	src/main/org/nlogo/window/DummyChooserWidget.java
	src/main/org/nlogo/window/DummyInputBoxWidget.scala
	src/main/org/nlogo/window/GUIWorkspace.scala
	src/main/org/nlogo/window/InterfacePanelLite.java
	src/test/org/nlogo/lab/gui/ProtocolEditableTests.scala