Enhancing temporal aspects

[GMMULLER]

• [x] Modify all thematic functions to enable the generation of more than one timestep.
• [x] Include multiple timesteps into the plots
• [x] Modify UTK to load multiple timesteps. UTK should understand one timesteps and multiple timesteps
• [x] Modify utk-ts to handle multiple timesteps
• [x] map: add procedure to update current function and update the values on the gpu (shaders) - updateShaderData has to be called again - bindVertexArrayObject has to be called again
• [x] Include multiple timesteps into the map (slider)
• [x] Update documentation