whereisOrStart is not safe in presence of asynchronous exceptions

[qnikst]

whereisOrStart is not safe it's not safe if exception is sent to caller then it may die before sending
(), so newly registered process will wait forever, and no other processes may be registered, until someone will kill problematic process

[hyperthunk]

I don't really use whereisOrStart, so I'm happy to drop this, along with Call.hs too.

[hyperthunk]

Actually I'm using Call, but I'd like to get off it. In order to do that, I need a whereisRemote implementation that isn't insanely complicated. Will raise a ticket for that.