Added mds layout for glyphs.  Right now there are some performance issues in the mds algorithm so I am holding off merging to the main branch.
Fixed attribute mapping issue.
Small changes to MDS layout to improve layout of glyphs.
Fixed issue with config file loading.  Added in Principal Components Analysis layout as an option to use instead of MDS.  PCA is a lot faster but has some layout issues that I'm still working on.