Changes to post processor

• Added support for high/low accuracy mode for CAMplete APT post.
• Added support for high/low accuracy mode for XML post.
• Added property 'useG0' to switch between rapid and high feed moves for Mach3 plasma post.
• Added property 'useFixtureOffsetFunction' to use CALL OO88 for 3+2 machining for Okuma post.
• Operations that use SFM spindle speeds will not output an RPM speed until the first position of the operation is output to prevent very low spindle speeds for OKUMA LB3000 post.
• Fixed property 'makeAAxisOtherWay' for HAAS with A-axis post.
• Output G31 for each cut for Mach3 plasma post.
• Updated coolant and retract handling for posts.
• Updated coolant and retract handling for Siemens 840D post.
• Allow 3+2 machining without a machine defined for Siemens 840D post.