update models library
Documenting risky Windows/'export-world' usage (fixes #339)
add agentset type checking to link creation prims

fixes #338
Merge remote-tracking branch 'origin/5.0.x'

Conflicts:
	src/main/org/nlogo/prim/_createlinksfrom.java
	src/main/org/nlogo/prim/_createlinksto.java
	src/main/org/nlogo/prim/_createlinkswith.java
	test/benchdumps/ImportWorld.txt