This adds quotes around multiword arguments before they are passed to
`/bin/sh -c` in an exec command.
Example:
I connect to irc like this:
exec termite -e "mosh server tmux a"
Without this patch the arguments are passed to sh as:
termite -e mosh server tmux a
When it should be:
termite -e "mosh server tmux a"
For the command to work.
