set terminal raw when spawned with tty
slight cleanup in iodaemon tty test
de-flake tty resizing test
do not allow setting window size until linked
refactor process initialization flow

* only construct the pty/pipe when linking, not in initializer
* close process's end of pipe/tty after spawning; parent doesn't need it
remove unused dep
fix leaking of stdin file descriptors
fix race in process tracker