JS test: added test utils
JS test: removed legacy inline tests
JS test: JS AST access from tests
JS test: added inline tests
JS test: turn rhino optimization off for stdlib tests
JS backend: added visitors with context
JS backend: break label should be JsNameRef, not String

The reason is to make it easier to distinguish
between different break labels (that's valid on same level).
JsNameRefs can be distinguished by their JsName.
JS backend: added NotNull annotation
JS backend: made JsInvocation arguments modifieable
JS backend: made JsBlock statements list modifieable

Inliner should be able to add statements of inline function to JsBlock
JS backend: made JsScope hasOwnName method public
JS backend: removed JsBlock toString() truncation

Truncation complicates debugging.
Some inline tests depend on functions strings  comparison.
JS backend: added deepCopy() method to JS AST nodes
JS inline: removed legacy inline logic
JS inline: save inline status during translation
JS inline: added InlineableResult
JS inline: added FunctionInlineMutator
JS inline: added JsInliner
JS inline: save static ref to JsFunction in JsName
JS inline: collect defined functions