remove debugging output
beef up StructureParserTests with some passing tests

adding them since they're going to fail once merged to master;
it's #414
Merge remote-tracking branch 'origin/5.0.x'

Conflicts:
	src/test/org/nlogo/compiler/StructureParserTests.scala
	src/test/org/nlogo/headless/TreeAgentSetTests.scala
fix StructureParser regression (fixes #414)
Merge remote-tracking branch 'origin/master' into core
add passing ExpressionParser test showing existence of issue #417

I'll fix the bug and update the test case in a subsequent commit
fix ExpressionParser bug -- fixes #417
Merge remote-tracking branch 'origin/core' into headless

Conflicts:
	headless/src/main/org/nlogo/parse/StructureParser.scala
Merge remote-tracking branch 'origin/issue-417' into headless

Conflicts:
	src/main/org/nlogo/compiler/ConstantParser.scala
	src/main/org/nlogo/parse/ExpressionParser.scala
	src/test/org/nlogo/compiler/ConstantParserTests.scala
	src/test/org/nlogo/parse/ExpressionParserTests.scala
	test/benchdumps/CA1D.txt
	test/benchdumps/GasLabCirc.txt
	test/benchdumps/GasLabNew.txt
	test/benchdumps/Ising.txt