1.5.0.7: Adding pool size to BackgroundTreadsRunner class and adding silent String to Number parsing methods to TextUtils

In this release class BackgroundTreadsRunner now has pool size property so it could be created with pre-defined pool size or as it used to be with default one if this property is not set. The default pool size is the number of tasks submitted to the pool. Also in TextUtils all String to Number parsing methods now have silent versions where they just parse the String to numeric value or if String is not valid they return default value, but nothing is printed into log.