Add M203 to change max feedrates on the fly. Saveable with M500
Merge pull request #319 from wolfmanjm/upstreamedge

Add M203 to change max feedrates on the fly. Saveable with M500. Also wait for queue empty before changing accleration with M204
change minute -> second in relevant comments
Arm solutions: use appropriate constants
Parsing of relative path corrected

absolute_from_reletive() now returns an absolute path that accounts for
../ and ..  in relative paths
Removed incorrect addition of trailing / from folder in cd_command()
Merge pull request #320 from gkbeer/edge

Parsing of relative path corrected
extend gkbeears fix for cd to player.cpp
Merge pull request #321 from wolfmanjm/upstreamedge

extend gkbeers fix for cd to player.cpp
fix M26 and M23
Merge pull request #322 from wolfmanjm/upstreamedge

fix M26 and M23
updaye from Wulfnor fixing epsilon
Merge pull request #323 from wolfmanjm/upstreamedge

updaye from Wulfnor fixing epsilon
added laser_module_pwm_period config setting which adjusts the pwm rate by setting the pwm period in microseconds