Border-less tight subplot (auto-refresh)

Creates subplot axes similar to the subplot function, but minimizes the white space between the different axes. Similar to the "Expand axes to fill figure" command in the export tool but works for subplots too. The white space removal is performed when the figure's 'SizeChangedFcn' callback is executed. Initiates when figure becomes visible for the first time. Automatically refreshes each time the figure is resized.

Use subplotXmanyY_er for plots with mutual x-axis.

Can be used for single axes figures too.

Note: Not compatible with legends/colorbars outside the axes borders. Must use 'inside' legends/colorbars.