Feature/probability distribution decorators

[apmccartney]

Added compile time decorators for probability distributions. See the Decorator Design Pattern.

These decorators modify the behavior of the probabilityDensity and cumulativeProbability of the composed probability distribution instance. Four decorators are provided:

• ProbDistLeftInterval The probability density of events to the left of the specified value evaluate as zero. The cumulative probability of events to the left of the specified value evaluate as zero.
• ProbDistRightInterval The probability density of events to the right of the specified value evaluate as zero. The cumulative probability of events to the right of the specified value evaluate as one.
• ProbDistLeftDomainBoundary Querying the probability density or cumulative probability of events to the left of the specified value cause an error to throw
• ProbDistRightDomainBoundary Querying the probability density or cumulative probability of events to the right of the specified value cause an error to throw

A probability distribution template has been provided to accomodate data specified in terms of an arbitrary number of equiprobable bins. The template is specified in terms of an ownership policy and hence can be provide data ownership or reference data owned otherwise.

BivariateProbabilityDistribution API and implementation template have been renamed ConditionalProbabilityDistribution

[jlconlin]

Looks pretty good, but there needs to be some documentation explaining the new decorators. Otherwise, someone may not know how they should be used or when.