Implements IPriceVariationModel interface which takes the security object and returns a decimal variation
Implemets SecurityVariationModel class: default implementation of IPriceVariationModel that returns a fixed value (read from symbol-properties-database) for decimal variation
Implemets EquityVariationModel class: implementaion of IPriceVariationModel that returns a decimal variation as a function of equity price
Implemets AdjustedPriceVariationModel class: implementaion of IPriceVariationModel that returns zero
Adds unit test
Stefano Raggi