Correcting setup installer configuration.
Adding better specifications to Gamma functions.
Adding a dedicated InverseDistributionFunction to ChiSquare and Gamma distributions.
Adding the inverse chi square distribution.
Expanding the available Circular measures and adding CircularDescriptiveAnalysis.
Working on documentation.
Updating ID3 learning algorithm to allow attributes to join multiple times the decision process.
Merge remote-tracking branch 'upstream/development' into development
Merge branch 'development' into portable

Conflicts:
	Sources/Accord.MachineLearning/DecisionTrees/DecisionNode.cs
	Unit Tests/Accord.Tests.Statistics/CircularTest.cs
	Unit Tests/Accord.Tests.Statistics/Distributions/Univariate/Continuous/ChiSquareDistributionTest.cs
Modifications to comply with latest merge