Adding Gyre mode as option in Globals and DCPump

This pump mode is kind of a combination of LongPulse and Sine.  It gradually ramps up to the full speed and then back down on the sync channel over the duration given in minutes while keeping the anti-sync channel turned off at 0, then switches and does the anti-sync one while the sync one is at 0.  

Note: the duration is in minutes, not seconds because users wanting a gyre effect may want to go for more than 255 seconds when using DCPump to control it.  

It is of use to those of us who have pumps in the back corners of our tanks, and will also be of use to new users of the CoralVue Maxspect gyre pumps when the inevitable controllable form of those come out.