Re-arrange version information and splash screen: show build date in yy/mm/dd format; put version and revision numbers on the same line
LEFT button now returns to parent menu when in a subfolder
Performance improvements for planner; remove superfluous max normal and extruder only accels.  First most users don't understand them.  Second, they default to >= the per axial limits in which case they are always overridden by the max accel for the axis with the most steps.  They only have an effect if set lower than the max axial accels, but it is unlikely anyone does that knowing the impact of so doing (especially given the first issue -- lack of understanding).