Optimised version of KNN for Euclidean distances

This patch also:
   * Completes removal of the edf/ package
   * Corrects an erroneous print statement
   * Introduces two new CSV functions
      * ParseCSVToInstancesTemplated makes sure that
        reading a second CSV file maintains strict Attribute
        compatibility with an existing DenseInstances
      * ParseCSVToInstancesWithAttributeGroups gives more control
        over where Attributes end up in memory, important for
        gaining predictable control over the KNN optimisation
      * Decouples BinaryAttributeGroup from FixedAttributeGroup for
        better casting support
Merge pull request #87 from Sentimentron/knn-opt-staging

Optimised version of KNN for Euclidean distances