OPENDJ-2748 OPENDJ-1667 dsconfig --displayCommand should print a usable command and parse it correctly afterwards

Printing the command should not wrap it on the terminal, otherwise embedded spaces could be lost.
Parsing the command back, either batch file or stdin, requires handling escape sequencing and double quotes around multiword values.
Add unescaping of sequences even in multiword values, to take into account shell escapes.