Add support for "cmd1 ... | passh cmd2 ... | cmd3 ..." ?

[clarkwang]

sshpass is quite happy with pipes, as mentioned in README.md.

[clarkwang]

The current behavior is intentional. I don't want people to think that the following usage would work as expected:

passh cmd1 ... | cmd2 ...

Simple example:

$ sshpass echo hello | hexdump -C
00000000  68 65 6c 6c 6f 0a                                 |hello.|
00000006
$ passh echo hello | hexdump -C
00000000  68 65 6c 6c 6f 0d 0a                              |hello..|
00000007

You can write like this (as mentioned in README.md):

passh sh -c 'cmd1 ... | cmd2 ... | ...'