#1 Add coefficient parameter

[rodrigosetti]

Test coefficient parameter.
A float number parameter assigned to every spring. This number multiply the angleoffset value before it is added to offset parameter and get sine to be calculated.

The expected result is springbots developing springs moving in different frequencies, but a warning is that maybe springbots evolve such parameter to be as big as possible to act like fast-forward. To avoid this maybe the fitness functions have to add a penalty(energy use) on abusing this number(and maybe amplitude as well).

Anyway, tests will be necessary.