New/modified core entry points for soft limit checking.
More delta robot tuning, added setting warning in $DELTA output if some settings are inconsistent such as steps/rad, acceleration etc.
Fix for issue #361, HOME status is not reported or reported late when auto reporting is enabled with setting $481.
Some drivers will now only disable hard limits (if enabled) for axes that are homing, this includes max/min limit switches.
HAL entry points and core handlers/events has been added and some have changed signatures in order to better support kinematics implementations.
More work on delta kinematics: new and changed settings, some improved functionality. Still in progress.
Added free memory to $I output when available, example: [FREE MEMORY:102K]
Changed reported position for failed probe to target. Parameters #5061 - #5069 returns position in coordinate system used when probing.
Added spindle type property to HAL, "hardened" code.
Added new setting $346 for action to take after tool change: either return controlled point (tool tip) back to the same position as before the M6 command (default) or move spindle to Z home.
