correct token count, ctrl-D segfault fix, exit arg count check
printing token bugfix
able to exec and wait for multiple external programs.
working pipe
ctrl-d has problem
shell get to its own process group
each pipe line get a process group
preliminary "jobs" command
A linked list of jobs
code refactoring in interpreter()
original pipe fd closed before exec
try to remove job, still buggy
working job control, including "fg" builtin command
job control,buggy
bug fix
Full job control.
fix fg 1 bug when there is no job
count remaining child correctly.
refctoring