Fix not compatible "--" specification problem (BSD versions chmod) | …

[uru2]

…fix #195

43c75ff add a -- flag, to treat all input as file or folder or drive id input bug.

BSD versions chmod (strict arguments parser)
$ chmod {mode} -- {file} <-- NG (change permission "--" file)
$ chmod -- {mode} {file} <-- OK ({option} arguments not used)

See chmod synopsis and utility syntax guideline 10.
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/chmod.html#tag_20_17_02
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_02

[uru2]

Add oneliner case statement fix for POSIX version.

e.g.

val=1234567890
val="${val#1}" val="${val%0}"
echo "val=${val}"

bash, dash implementation
val=23456789 (All expressions)

FreeBSD /bin/sh implementation
val=123456789 (Last expression only)