* Features
- new functions 'tr7_play_file' and 'tr7_play_string',
similar to 'tr7_(load|run)_(file|string)' but with fine
tuning options and funny name.
- support of colon prefixed SRFI number (see SRFI 97)
- new procedure (list-copy* L S E E) in (tr7 extra)
- new syntax (check-types BOOLEAN) in (tr7 extra)
- new procedure (tr7-keep-playing) in (tr7 trace)
* Changes
- forward generation of byte code in bytevector (#20)
- tr7i stops on first error when loading scripts and report it
in its exit status
- for-each procedure family now returns nothing
- setting record values now returns nothing
- improved implementation of records
- split of stack in two parts: data and operand
- use of callself optimized for tail calls or not
- use less memory for local variables by spoting scope
- separation of local variables and closure variables
- better report of errors and lines
* Fixes
- detection of misplaced definitions (#18)
- global safety stack