Esprima: merge origin + destructuring defaults

Merge latest origin:harmony to local version of esprima parser
Add experimental destructuring defaults support to local esprima
!!!EXPERIMENTAL!!!
Refartoring [addToScope] methods + some core functions

+ unwrapSpreadDeclaration
+ definitionWithDefaultString
+ defaultString
+ stringFromSrc
fix run-tests
Added file with examples which not supported by esprima
Refactoring <plugin>.setup | [addToScope] SpreadElement

Calling <plugin>.setup for all plugins before first plugin launch
Right behavior for SpreadElement when adding to scope
Rewrite destructuring | destructuring defaults (!experimental!)

More destructuring tests
Handle destructuring in one function
Added !!!EXPERIMENTAL!!! destructuring defaults support (should be
rewritten in the future)