Fix for heat hold timeout, interrupting filament loading post cancelled build, as well as during any other onboard process
updated current_version and 7.5.2 dist
Another change to have heat hold behave correctly in all scenarios
Re-adding code that shouldn't have been removed, and new hex files
Updating Rep1(Dual) startup script to make sense with new dual startup procedure, 7.5.4 dist
Merge branch 'master' of github.com:makerbot/MightyBoardFirmware