add st7565 support
add selection of st7565
fix glyph display
Merge pull request #232 from wuflnor/edge

add st7565 support
Made M17 and M18 apply to extruder as well as steppers.
M18 and M84 now accept E to disable only the extruder, not the steppers.
Merge pull request #235 from TopherMan/feature/extruder_disable

Feature/extruder disable
add mem command to see free ram

Conflicts:

	src/modules/utils/simpleshell/SimpleShell.cpp
Merge pull request #236 from wolfmanjm/upstreamedge

Upstreamedge
Merge remote-tracking branch 'upstream/edge' into working

Conflicts:
	src/modules/utils/simpleshell/SimpleShell.cpp
Clear the config cache just before the main loop starts, after all setup is done
Merge pull request #237 from wolfmanjm/upstreamedge

Clear config cache just before main loop starts
Merge remote-tracking branch 'upstream/edge' into working
Added Adams Heapwalk to determine amount of unallocated malloc memory