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

This reverts commit c14365be108058d0733ad088f66089ce04ddaaa9.
Revert "Merge pull request #28 from athieme/acceptors"

This reverts commit 40f1934df9d77cb4734b214a14ab9e0d44b02517.