updates to get CSim building on ubuntu, need to be sure to find zlib before libxml2 so that our zlib is used rather than trying to find one on the system.
updates to get CSim building on ubuntu, need to be sure to find zlib before libxml2 so that our zlib is used rather than trying to find one on the system.

nickerso/csim,nickerso/csim,nickerso/csim-v2,nickerso/csim-v2,nickerso/csim-v2,nickerso/csim