Move test JS into HTML files

Fixes #896.
Fix some missing end-of-file newlines
auto merge of #958 : tikue/servo/master, r=pcwalton

Cells are generally less readable, and spawn_with makes many of them unnecessary.
auto merge of #957 : kmcallister/servo/inline-js, r=jdm
deactive profiler when not in use; implement GenericChan and GenericSmartChan for task channels