Serial Upper Half:  Add watermarks to RX flow control logic
Updte ChangeLog
Eliminate an unnecessary calculation in the serial RX flow control logic
Serial RX Flow Control:  Fix a bunch of compile problems introduced into unbuilt, conditioned out logic
Remove STM32-specific RX flow control logic from the upper level serial driver to the lower level STM32 serial driver
STM32 Serial: PX4 HW workarround for flaky STM32 RTS.  From David Sidrane
Update README.txt
Update README.txt
STM32F40G-EVAL: Refresh two configurations, turning off DEBUG
STM32F429-Disco: Refresh five configurations, turning off DEBUG
Eagle100: Refresh one configurations, turning off DEBUG
Freedom KL25Z: Refresh one configurations
LM3S6965-EK: Refresh one configurations, turning off DEBUG
Mikroe-STM32F4: Refresh one configurations, turning off DEBUG
Semahores:  Remove a warning with SIGNALS are disabled
Semaphores:  sem_waitirq.c must be built when signals are disabled.  That is because not handles not only the case of semaphore wait being awakened by a signal, but also the case with sem_timedwait.c when the semaphore wait is awakened by a timeout.
Update ChangeLog
Don't build pread()/pwrite() if file system support is disabled
Serial:  Allow serial console selection even if /dev/console is disabled:  There can still be a serial console with no file system at all
Freedom-KL25z: Fix breakage from last configuration refresh