* add option to Flush() to only clear txQueue
Add the option to cause Flush() to just wait for tx data to clear the tx fifo and uart, leave the rx queue and rx fifo as is.
* support tx only flush()
* support tx only Flush()
* support txOnly for Flush()
* compatibility to Stream()
* compatibility for Stream()
* default value error
* default value error
* Update esp32-hal-uart.h
* Update esp32-hal-uart.c
* Update HardwareSerial.cpp
* sp
* correctly implement flushTxOnly()
* Expose uartStartDetectBaudrate(uart_t *) in esp32-hal-uart.h and call it from HardwareSerial::begin() if baudrate detection is requested (by passing a baudrate of 0) to solve baudrate detection problems
* Avoid a division by zero error in uartGetBaudRate()
* Added baudrate detection to esp32-hal-uart and HardwareSerial
* Solved compiler warning for uartResizeRxBuffer()
* Add unit to header variable name (timeout_ms)
* Reverting accidentally changed files to master
* Add small delay after baudrate detection
