PIPE command doesn't start the process

[vuori]

Running a trivial command with /PIPE, such as PIPE cat immediately shows that connection ended. strace -f seems to indicate that a process is forked, but instead of calling exec the new subprocess just exits.

PTY works as expected, but is not suitable for all uses.

Tested on 10.0beta08 built with make linux+ssl.

[vuori]

Attached patch seems to fix this. exec_cmd prototype should be put somewhere better.