JsInline: added FunctionCollector
JsInline: added InlineableResult
JsInline: added FunctionInlineMutator
JsInline: rename repeated local names
JsInline: save static ref to JsFunction in JsName
JsInline: alias arguments of inlining call
JsInline: replace return statements with break on label
JsInline: JsBlock must be modifieable

Reason: it is ok to insert in a block after AST was created during translation.
For example, inliner can insert inlined body in such block.
Thus immutable SingletonList isn't appropriate.
JsInline: added JsInliner
JsInline: save block contexts to stack

Reason: need to be able to insert inlined body
before current statement (that might be
distant parent of node currently being
processed)
JsInline: save inline status during translation
JsInline: inline function calls
JsInline: run JsInliner after AST is built