* change GLOBAL_INSTALL_DIR to CMAKE_INSTALL_PREFIX

* use unquoted version variables in cmake install scripts

* comment out debug prints

* correct slic bin dir

* install ext dep sources directly in build dir

* add initial versions of CMake ExternalProject macros

* more work on getting external projects to work

* fix compiler definitions

* fix link libraries for slic target

* remove debug print outs

* cleanup top-level cmake file

* minor change to message

* remove unnecessary dependency variables from install scripts

update GDML cmake config

add slic env setup script

Update slic for Geante 10.3 compatibility