EUnit tests on windows opens a bunch of terminals then closes them

[nickva]

Both @big-r81 and I noticed when running make eunit apps=couch on Windows about a dozen terminal windows are spawned and then closed after about 10 seconds.

@big-r81 figured it out it's from opening "sleep.exe" commands. By default windows will spawn a terminal for those. We need to use the hide option in open_port to prevent it.

couchdb/src/couch/src/couch_debug.erl

Line 1127 in 5d4f3a3

Port = erlang:open_port({spawn, "sleep 10"}, []),

[nickva]

While looking at that test in the couch_debug module. There is likely another issue with it, where it doesn't cleanup properly its process tree:

couchdb/src/couch/src/couch_debug.erl

Line 1150 in 5d4f3a3

[exit(Pid, normal) || Pid <- Processes].

exit(Pid, normal) is a no-op effectively, so that leaves a bunch of processes around

[nickva]

These should be fixed now