added clustering algorithms and visualisation
merged updated project from kapec master to britvk branch
fixed build errors after merge
added qtcreator build directory to gitignore
added new shapes for clusters and sliders to filter clusters based on nodes count
added new spatial figure - dodecahedron
added automatic and user adjustable transparency for cluster objects
added ability to relocate clusters
added new custom spatial figures - sphere and spikysphere
added ui widgets to change clustering algorithm type and depth
added progress bar for clustering process
added custom cube spatial figure
pause graph layouting while clustering
cluster changes from transparent to solid when camera is inside
added cube restriction
minor fix - picking clusters
added cube restricion for selected cluster
added drag for cluster cube restrictor, when ctrl pressed drag changes size not position
shape and size of cluster now matches its restrictor - if it has one
changed default path for loading new graph