Revert "MULE-6988:  The jetty transport does not have an option to configure the number of acceptor threads"

This reverts commit e0e345eafa674362dae97095f25f1d27c48d9714.
Revert "Merge pull request #28 from athieme/acceptors"

This reverts commit fb1657f52efc40a70706641214ceda6513792df0.