+ Add new dict type and env_var_separator configuration.
+ Remove default environment map and replace with new configuration.
+ Use new configuration to determine separator to use.
+ New unit test for env var separator.
+ Merge cmake_module_path_special_case branch and fix conflicts.
+ Add missing import.
+ Extra extra backwards compatibility handling.
Merge remote-tracking branch 'mark/special_environment_variable_separators' into testing_1

Conflicts:
	src/rez/config.py
	src/rez/rex.py
	src/rez/util.py