Extensions for Kossel effector

Effector: http://www.thingiverse.com/thing:731354
Also tested with micromake effector (2015 version with Z-probe and on-effector fan mount) for the 30mm cooling fan(part cooling)

I modified the "Proximity sensor"(http://www.thingiverse.com/thing:966349) a little bit so that it would fit in the space easier

Upd 08/28/2016: added stops for the holders. Basically they are necessary to ensure the inductive holder and the fans are not moving