Merge pull request #399 from Smoothieware/edge

stable edge before multitool
update firmware.bin fir master
Merge branch 'edge'

Conflicts:
	FirmwareBin/firmware.bin
Added M204 Ennn to set extruder solo acceleration
Added flow rate and aextruder acceleration to panel menu
added firmware retract length to panel
Merge pull request #483 from wolfmanjm/features/add-E-acceleration-setting-add-to-panel

Added M204 Ennn to set extruder solo acceleration
add on_exit to panelscreen
have Configuration menu delete itself on exit (saves tons of memory)
have Extruder settings menu delete itself on exit
clean up header includes in headers for panel screens
Merge pull request #484 from wolfmanjm/features/add-on-exit-to-menus

add on_exit to panelscreen
make dtor virtual
Merge pull request #485 from wolfmanjm/upstreamedge

make dtor virtual
If no heaters presume no extruders and do not create extruder menu or temperature relted panel menu items
don't disdplay tmperatures on panel if no heaters
Merge pull request #486 from wolfmanjm/optimize/optionally-load-extruder-menu

Optimize/optionally load extruder menu
Add a probe screen to panel
shows endstops and probe status and initiates and display a G30 probe
Half hearted attempt at implementing M112 ESTOP
Merge pull request #489 from wolfmanjm/upstreamedge

Half hearted attempt at implementing M112 ESTOP
Merge remote-tracking branch 'upstream/edge' into add/probe-screen
Fix switch state sio it is false if PWM switch and S0
Merge pull request #490 from wolfmanjm/upstreamedge

Fix switch state sio it is false if PWM switch and S0
Merge remote-tracking branch 'upstream/edge' into add/probe-screen
DHCP option 12 support (hostname)