Fix UVW jogs being too fast by 25.4x, on inch configs displaying mm

Signed-off-by: Chris Radek <chris@timeguy.com>
Fix shift-jog speed being too slow on inch configs displaying mm

Fixes the second part of bug #397

Signed-off-by: Chris Radek <chris@timeguy.com>
Merge branch 'v2.5_branch' into 2.6