Fixed error when calling compute_correspondences

[prophecy]

This has 2 issues.

1. Compile time error when make a build using CMAKE on my Mac (Other OS should be the same) folling this line.
   _kdTree = new nanoflann::KDTreeEigenMatrixAdaptor<VecMatType(_inSourcePoints, _leafSize);
2. I fixed using this line
   _kdTree = new nanoflann::KDTreeEigenMatrixAdaptor<VecMatType>(_numDimensions, *_inSourcePoints);

By the way, I have removed _leafSize, which is an optional parameter, as it's kind of optimization purpose. I can make a new commit or make some tests if you prefer.

PS. I am currently considering to include MashMonk with my master thesis. I might do more tests or adjust some parameters. So, you can tell me if you need some more tests.

Thank you,

[T-AbdelAlim]

@prophecy Nice that you fixed this.
Any suggestions on how to apply this fix to Windows using the build steps described in the tutorial in Visual Studio?