CBashConfig.h: CBash setup macros moved here

* Moved most config-type macros from CBash.h and CBash.cpp to here
* Uses Boost's auto_link.hpp to automatically link to the required zlib binary
* You can still link against non-boost zlib by defining CBASH_NO_BOOST_ZLIB

**NOTE**: You'll want to edit your project settings after this commit to either
not explicitly link against the boost zlib binaries (if you were), or to define
CBASH_NO_BOOST_ZLIB if you were linking against non-boost zlib binaries.