Updated comments
Updated comments

1) Answered a question that was posed in comments, also noting the
   relationship to reference counting arrays of arrays.

2) Updated some comments that suggested the compiler introduced
   some calls that are really introduced by other modules.




git-svn-id: 88467cb1fb04b8a755be7e1ee1026be4190196ef@21190 3a8e244f-b0f2-452b-bcba-4c88e055c3ca

sungeunchoi/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,CoryMcCartan/chapel,hildeth/chapel,sungeunchoi/chapel,sungeunchoi/chapel,sungeunchoi/chapel,chizarlicious/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,sungeunchoi/chapel,sungeunchoi/chapel,chizarlicious/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,sungeunchoi/chapel