cep_negate_path should have a high weight

There are cases where cep_negate_path will conflict with other modules that alter the current page. An example is the context_reaction_front module, which alters the front page. Basically both of these modules can potentially conflict with each other and cause a context not to evaluate when it should. I think it makes the most sense for cep_negate_path to execute /after/ other modules that want to alter the paths have executed, as cep_negate_path should be executed on the /final/ path of the current page.

This patch simply adds a .install file to set the weight of the cep_negate_path module to be 10, so that other modules will run before it.