moved actions associated with unlock into lims_config.pl for central loading for app & templates, and coupled unlock function to associated actions in Resources / user permissions
replaced several calls to L::Local::find_home() with call to config instance; removed call to L::Local::Debug from lims_config.pl, as debug() uses config instance, which uses lims_config.pl; model classes get config from config instance instead of constructor passing it in LIMS::model(); general tidy-up
replaced multiple calls to load config settings with LIMS:Local::Config->instance(), using Class::Singleton to ensure config file opened & read only once at server startup
replaced multiple calls to load config settings with LIMS:Local::Config->instance(), using Class::Singleton to ensure config file opened & read only once at server startup
