* update grammar
* add ast nodes; ast building
* Rename to unpacking
* semantic analysis
* executor work part 1, unpacking indices
* renamings; implement index binding
* small cleanup
* use multi_index; more tests
* use multi_index only for rest, otherwise list
* initial formatting
* add missing token decoding
* address self-review comments
* formatting tweaks
* add test for var binding in classes
* add StringIterator
* fix spread tests
* add cfgfile iterator; add cfgelem opersubscript; tests
* add iterator for SQLResultSet and SQLRow; tests
* Copy value in take global/local
* Allow any iterable can index rest unpacking
Always use dictionary as rest object in index unpacking
* add docs, core-changes, doc tests
* formatting changes...
* address self-review comments
* update formatter, format all binding test srcs
* address review comments
- unset var scope
* add cfgfile/cfgelem docs
* reformat objref svg
