Merge pull request #209 from wolfmanjm/upstreamedge

Upstreamedge
Increase glcd refresh rate to 10Hz
Allow trim values to be negative to trim up
Fix home_direction to be bool in all cases, lucky it worked using it as int
Add M206 to adjust trim values (in mm) on the fly
Only show endstops that are used (either min or max)
Negate trim depending on homing direction so + trim homes away from home
added hbot/corexy homing
Convert the endstop/homing configs to mm and mm/sec
update sample configs
Old config values in steps and steps/sec will still be accepted
add corexy_homing to sample config
udate delta config for homing
turn off both motors when endstop is hit for corexy
check both corexy motors for stop
remove last debug printf from homing
Merge pull request #210 from wolfmanjm/feature/hbot-homing

Feature/hbot homing
change config trim values sign to match that set in M206