* Mitigate stepper timeout

* Add CHAMBER PWM code

* Structured thermistor tables

* Fix reversed sensor ranges

* Prevent temps outside sensor range

* Enable hardware serial ports on LPC1768

* Fix compilation errors with other HALs

* FIx order of includes in LPC1768 HAL main.cpp

* Add support for RX_BUFFER_SIZE and TX_BUFFER_SIZE options in Configuration_adv.h

fix Travis error

Replace ARDUINO_ARCH_AVR with __AVR__ to better detect architecture for non-Arduino dev environments.  Resolves compile failure in PIO for 8-bit Teensduino targets

More info:
https://forum.pjrc.com/threads/33234-Using-Teensyduino-Selecting-Teensy-3-2-3-1-board-has-incorrect-platform-define
http://www.atmel.com/webdoc/avrlibcreferencemanual/using_tools_1using_avr_gcc_mach_opt.html

Implement AVR Platform

Replace all fastDigitalRead/Write() with READ/WRITE()

Define SCK_PIN, MISO_PIN, MOSI_PIN in pins.h if not already defined in the pins_*.h files.

Remove these conditional pin definitions from the pin-files. They are now always defined.

Define separate sets of SPI-pins for AT90USB with and without Teensy support in fastio.h.
Likely this was the main reason for all that confusion about the AT90USB-SPI pins.

Following up on #3231

Note that newer versions of the IDE can still
be made to support compilation for the older boards.

- Apply standards to cardreader.*
- Fix minor issues with cardreader.cpp
- Apply standards to some other stale regions

If only an LCD is defined and no menu or keyboard defined, there is a
compilation error.

Added conditional compilation.

Included support for BT dongle on AT90USB boards.
Added LCD Shift Register LCD control
Included support for RepRap Clone Wars project board (SAV MKI).