exporting settings from js/cs files to a dedicated Config

exporting settings from js/cs files to a dedicated Config global object, where settings are loaded at startup with the erb processor; I could use haml but it would require registering an additional asset pipeline processor:

Rails.application.assets.register_engine '.haml', Tilt::HamlTemplate

and I guess we don't need it for just that one erp file.

@mkasztelnik please have a look