Figures and Excel sheets for synchronization added.

I added the figures, graphs and excel files for cell number
synchronization and gravistimulation synchronization. The Excel files
are named dataset_raw_stimulationSynced.xlsx and
dataset_interpolated_stimulationSynced.xlsx and
dataset_interpolated_cellNumberSynced.xlsx. The cell number
synchronization is done for the interpolated data because otherwise it
would give strange results. I also added the other excel files for the
datasets. Each excel file contains the information about the object and
also some additional information like the cell file (TrackGroup).