Created branch for ticket #615
Added the ticket #607 to the changes log.
Added the commands to load the new language file numere.nlnp that contains parts of the previous main.nlnp language file. The new language file structure that made this change necessary, is described in ticket #607.
Added the change log entry for the "clc" command as described in #624.
Added the clc command that allows to clear the terminal and resets it to the startup state according to ticket #624.
Implemented ticket #605 "Use Savitzky-Golay for taylor"
Implemented ticket #632 "Resolve the 'GraphViewer-Zoom-Bug'" Additionally, resolved a timezone issue introduced with #628
Implemented ticket #643 "Add buffer to 2D smoothing"
Improved implementations #618, #601 and #628 Additionally sped up some matrix operations
Fixed the docstring for `strfill()`. In reference to #618.