Fix jerky SD card printing when no network cable

Fixed problem whereby gcode files printed from SD card that used lots of
small fast moves in sequence would print jerkily if a network cable had
not been connected since reset.
Fixed problem whereby object height and filament needed were not
retrieved from the SD card file to be printed if the filename contained
spaces.
Added support for deprecated M190 command, because slic3r appears to
generate it sometimes
Added support for M564 command to allow movement without limits, copied
from RepRapPro dev branch