make the spawn driver use os:setenv values
Make sure eof / {exit_status, _} is last

There was a race condition between the Thread
reading stderr and the one reading stdin.  The
stdin reader should wait until the stdout thread
exits before sending elf / exit_status.
Fix argument processing for port({spawn, "…"}, …)

We now actually process quoted arguments, as well
as escaped quotes within such arguments.
Make Erjang print stack traces on kill -HUP <pid>

Super useful debug tool like Java's kill -QUIT