[PATCH v2] Reduce false positive in check-non-portable-shell.pl

check-non-portable-shell.pl is using simple regular expressions to find illegal shell syntax. Improve the expressions and reduce the chance for false positves: "sed -i" must be followed by 1..n whitespace and 1 non whitespace "declare" must be followed by 1..n whitespace and 1 non whitespace "ech

[PATCH v2] Reduce false positive in check-non-portable-shell.pl

check-non-portable-shell.pl is using simple regular expressions to find illegal shell syntax. Improve the expressions and reduce the chance for false positves: "sed -i" must be followed by 1..n whitespace and 1 non whitespace "declare" must be followed by 1..n whitespace and 1 non whitespace "ech