Changed flags.

cublas and cula now only linked when compiling for parallel.
Updated force-atlas-2.c for new data structures.
Updated makefile again. Removed cuda specific code
Created stubs for all functions.
Implemented sequential util functions.
Removed unused code.
Implemented sequential smoothening.
Implemented sequential vector average.
Implemented sequential break-edges.
Implemented sequential connected component.
Added documentation.
Renamed function.
Updated documentation.
Added libalglib to implement sequential pca.
Implemented sequential pca.
Removed bugs and compile errors.
Removed bug from parallel pca.
Removed some print statements.
Removed bug from sequential pca.
Added debug prints, removed a bug from attraction