BUG: Brim doesn't work with elephant foot compensation

Brim-object gap parameter should adjusts itself according to elephant foot compensation’s parameter, but it doesn’t. Brim fails connect to 1st layer if larger elephant foot compensation is used which is a must for 0.6 and 0.8 mm nozzle. Please make it priority to fix this.

A short term fix is to allow negative parameter in Brim-object gap, users can calculate it manually.