Real depending.

SimplyJetpacks is an addon for Thermal Expansion, but depends on CoFH Core, and to use CoFH Core, it includes needed CoFH Core classes when building (open SimplyJetpacks jar file, and you'll find "cofh" folder, that contains needed classes), and therefore, SimplyJetpacks can be started without Thermal Expansion or CoFH Core. This patch fixes that, and SimplyJetpacks can't be started without Thermal Expansion.