Merged in zpl's latest changes to Network and Print Monitor modules,
providing DHCP and Netbios name support
Added command M999 S4321 to unlock flash memory, reset and boot to BOSSA
port
Z dive height is now relative to Z probe trigger height and default is
reduced to 3mm
Added experimental support for acoustic probe for delta printers
Bug fix: firmware once again prevents Z homing before X and Y are homed,
if the Z probe is used for Z homing
Various code tidying
Changed webserver to support HTTP requests that span multiple TCP
messages. Changed upload code to to block file writes direct fro the
received message. Increased maximum upload message size. Changed
fileinfo command to report layer height and what program generated the
gcode file, if available.
Incoming network requests can now span multiple TCP messages. Max upload
buffer increased to 2048. Also return layerHeight and generatedBy values
when asking for fileinfo on a gcode file. This is an interim commit that
needs cleaning up before release.
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
Changed network startup to avoid long delay if no network cable is
connected
Enable DHCP support if IP address is configured as 0.0.0.0 (not working
yet)
Move thermistor parameters to M305, added parameter to configure series
resistance
Added B and W PID parameters
