Added shell parser to separate entry and args for command

[vietjtnguyen]

Tested with a somewhat strange node app.js -c "/bin/bash -xc \"echo hello & /bin/bash\"" -p 80 and got the expected output:

+ /bin/bash
+ echo hello
hello
[root@fbffe09cdd9b wetty]# 

[samuelson]

Can you help me understand why this is needed? I think I would prefer to use a script as the command rather than add more complexity to the app itself.

[samuelson]

Also, I don't really want to merge anything until this is merged upstream.

[vietjtnguyen]

It's just sort of canonically extensible. This way I can now run

node app.js -p 80 -c "tmux attach"

in my Docker container to attach to interactively inspect and check my long running process. Sure you can create a shell script

echo "#!/bin/bash" >> tmux-attach.sh
echo "tmux attach" >> tmux-attach.sh
chmod u+x tmux-attach.sh
node app.js -p 80 -c ./tmux-attach.sh

but it seems a little unnecessary to me.

Feel free to defer this until your current branch state is merged.