ref: b548687a8ed1d0a159c9d3f3f921d93bbb56908e
dir: /appl/cmd/sh/doc/History/
14/11/96 started 12/12/96 first mostly working version 13/12/96 fixed bug in builtin_if 14/12/96 prompt fixed, dup fixed. 17/1/97 fiddled with shell script perm checking 16/2/97 converted to yacc grammar 18/2/97 got pipes and backquotes working, with only minor hacks... 2/4/00 revamped: single process, single main module; added load builtin; added ${} operator; added eval and std modules 17/4/00 added '=' and ':=' operators; removed builtin 'set' and 'local'. 11/6/00 added tuple assignment 2/3/01 added n-char lookahead in lexer; ':' no longer so special 15/2/01 store environment variables in standard quoted format.