Usage:
despline(ax, offsetfactor)
ax: axes handle
offsetfactor: can be a number or 2-element vector ([x,y])
despline(ax); % offsetfactor = 1
despline(offsetfactor) % ax = gca
despline([ax1, ax2, ...])
despline([ax1, ax2, ...], offsetfactor)
despline(fig_handle)
despline(fig_handle, offsetfactor)
despline('all') % 'all' is equil to all axes in gcf
despline('all', offsetfactor)

Inpiration: offsetAxes by Anne Urai, 2016
https://www.mathworks.com/matlabcentral/fileexchange/52351-offsetaxes-ax

Modified by Tuan Pham, 2019
- Oct 06, 2019: fixes to adapt to log scale, add offsetfactor
- Oct 25, 2019: fixes minor bugs
- Jan 04, 2021: add missing function
Note:
- For stable usage, set the limits and scales of the axes before using.
Minor ticks still unstably controlled (unnecessary minor ticks may
disappear after the first limit setting - meaning may not redrawing
minor ticks smaller than lower bound of limit)
- Currently not including Z axis