Fine Tuning Figure Toolbar

Toolbar to fix axis poisition so as to remove annoying blank margins. Also, set precise figure size.

The first buttons set of this toolbar allows to get rid of the annoying blank margins between axis and figure limits. The second buttons set allows selecting the exact figure size (width and height) in order for the figure to exactly fit in a scientific article, report or tesis (without wasting a lot of time on manually fine-tuning to get the same result).