[jsdl-wg] Updated Limit Specification

Here (as I promised in the last telecon) is the updated limit specification (it's a replacement for section 5.7.2 of the spec). It tightens up the meaning of what limits should be (it gives pretty strong statement about how to impose them!) and adds two examples too. One point of note about limits is that processes usually just get sent a signal or get an error out of a system call when they are exceeded. This gives the application a chance to modify its behaviour or clean up after itself, and is distinct from having a job managing engine decide that a process has taken too long and blowing the process out of the water with a SIGKILL... :^) Donal.