* Moved implementation data structures to datastructures.ss
* removed filenames from info, use index instead
* fixed a bug in StringIO strings
* Optimizations on strings
* Show verbose output when selecting filtered assertions in run-tests
* added new string-join
* Show exception on do_execute_file()
* Add data_files for kernel.json install
* Added ~ home expansion in cd (python)
* assert now raises AssertionError
* Allow test group names to be strings; allow partial matching
* New (host-environment)
* Added (hasitem)
* check for duplicate unit test group
* new (clear-unit-tests)
* New define-syntax via function
* Added (get-completions), (macros); removed macros from dir
* memv should use eqv_q
* Cleanup of exit/quit: tell users to ^D
* Use correct help_obj in jupyter