Super softtakeover

This introduces soft takeover for the super knob effect parameter connection. 
The super knob jumps to the current value of the linked parameter on effect load. 
https://bugs.launchpad.net/mixxx/+bug/1329063
https://bugs.launchpad.net/mixxx/+bug/1335355

It also includes some soft takeover refactoring 
src/util/time.h:26:32: error: static member function ‘static uint Time::elapsedMsecs()’ cannot have cv-qualifier

Found this:

> A static member function does not have a this pointer (such a function is not called on a particular instance of a class), so const qualification of a static member function doesn't make any sense.