fix use of obtain_ec_for in easyconfig test
add get_software_root_env_var_name and get_software_version_env_var_name functions, move 'EBROOT' and 'EBVERSION' into constants
moar log info on failing test
add allow_system_deps easyconfig parameter, fix use of self.config to self._config
add robot path to list of paths for easyconfig files
Merge pull request #478 from boegel/allow_system_deps

fix broken unit tests, add support for allow_system_deps