docs: Reference Adafruit NeoPixels for LED Strip

* Initial testing with NeoPixel Jewel 7s.
Merge pull request #188 from kylemanna/docs

docs: Reference Adafruit NeoPixels for LED Strip
Pindebug support

Allows state monitoring on selected pins during development, no overhead during production build

Used pins are reserved (needs some work)
Replace MODE_BIDIR with MODE_SINGLEWIRE

BIDIR mode is replaced with SINGLEWIRE mode. Semantics is slightly changed - MODE_SINGLEWIRE does not imply MODE_RX or MODE_TX, just that single pin (TX) is used for communication.
pwm_rx - use new channel interface
Refactor `callback` to `rxCallback` in serial code
Add timer_input, timer_output, timer_queue, callback
Refactor timer code
new softserial code
serial code - handle used port constants correctly
timer queue - allow no-remap on timer channel

usefull to initialize channel for timer queue
timer - add CNT register access function
Timer mode switching fix

stdperiph library is not resetting bits left over from input mode
Finished timer fix
Port capabilities updated in io/serial.c
remove hott softserial workaround
smartPort telemetry on sotserial

Added support for softserial port. Migration version now, needs some improvement for final version
moved timerqueue timer away from TIM1, temporary fix
GPS - enable TX when switching from mnea to ublox
gps.c whitespace
Fixed problem with USART3

GPIO register was not using symbolic name