Update BaseCostFunction and meanSquare

[Niklas Korsbo]

BaseCostFunction? needs the following functions:

void updateCost(tensor y)

• takes input from each time point at which the simulator

double executeCost()

• get the cost into a double
• call resetSimulationMemory()
• returns the calculated cost value

void parseCostParameters(inputstream)

• parse the type of cost function, then allow specific parameter parsing. if we do not need any parameter except the string defining the cost function to use then this may be parsed in the BaseCostFunction?. Otherwise, it must be inherited.

void resetSimulationMemory()

• specific to each inherited class, but should basically reset the information it stored from the simulation so that this information does not contaminate the next simulation result.

use meanSquare as a test case of an inheriting object.

BaseCostFunction::meanSquare

• containing specific versions of all the required above functions.