sh.lang: Improve and homogenize boundaries; cleaning
- Set "keyword-char-class" to
[^()`&|;] - Introduce regex "unescaped-space":
(?<!\\)\s - Redefine redirections
- Simplify stand-alone variable definition: space-separated variable assignment can also be preceded by an other variable assignment, or by a redirection; so the simplest way to define it without forgetting any case seems to use "unescaped-space" regex.
Edited by Gaël Bonithon