add IIterator
add TIterator
add IteratorAdapter
comment correction
add IKeyAccessor
add TKeyAccessor
add TArrayAccess
rename Object methods
init Objects
implement Objects::each()
implement Objects::filter()
implement Objects::reindex()
implement Objects::merge()
implement Objects::sort()
implement Objects::mergeA()
implement Objects::reverse()
implement Objects::extract()
implement Objects::diff(), Objects::diffA(), Objects::diffK()
implement Objects::intersect(), Objects::intersectA(), Objects::intersectK()
implement Objects::getByIndex(), Objects::first(), Objects::last()