Merged in zpl's changes. The FTP server is not yet reliable, in
particular trying to delete a file via FTP after copying another may
result in the Duet rebooting due to the webserver module getting stuck
in a spin loop. Also the copied file has on one occasion been observed
to be shorter than the original.
1. Reworked network layer to be more robust in the presence of network
errors (hopefully). In particular, don't release transmit buffers if
they might still be needed to retry sending data because the ACK got
lost.
2. Fixed bug whereby fileinfo command looked for the print height and
filament used if the extensio was .gcode or .gc or .gco but not if it
was .g.
3. When the M25 (pause print) command is received, pause the current
gcode so that commands such as M116 (wait for temperatures) can be
interrupted.
Fixed bug whereby incoming gcodes were URI-decoded twice, which could
cause problems if a comment contain a % character
Fixed bug whereby M109 and M190 waited for all heaters to reach target
temperature instead of just the one involved
Fixed bug whereby files whose names contain an uppercase letter G could
not be uploaded or deleted
Increase buffer size for incoming gcodes
Removed parameter to set max PWM value in M106 command. Max PWM value is
now 255 as per recent RepRapPro change.
Changed the code that deals with dropping characters in unimportant
messages sent to USB such that we only drop characters at the end of a
line (adding ".\n" to whatever we send) or drop whole lines
Completed changes to support multiple concurrent HTTP file requests.
Added support for new poll response for future support of additional
heaters and multiple extruders. Fixed a bug in reporting extruder
distance.
Changed webserver and network code to support multiple concurrent
connections
Removed support for differential-mode ultrasonic z-sensor
Reduced X and Y instantDv from 15 to 10 mm/sec to allow outlines of
holes to e drawn at lower speed
Changed temperature reading code to give thermistor disconnected reading
of -273C when there is a negative high ADC offset correction
Fixed bug introduced at version 057o-dc42 that broke the G32 bed
compensation. Added the Z heights of the bed compensation points to the
information displayed by M111 S2. Simplified the code that does
Z-probing in fast and slow stages. Added function sncatf and used it to
simplify the code in several places.
Added new fields "zprobe" and "resp" to webserver poll response
Immutable string parameters are passed as const char* not char*
Increase max number of files displayed to 42
Range-check heater parameters in incoming commands to avoid buffer
overflow if heater number is out of range
