* migrated stack diagnostics (available, free) to using built in FreeRTOS builtin function
Note: main stack must be and is treated differently as it is not under FreeRTOS control. main stack is painted by the STM32 startup routine. free main stack is calculated checking the remaining painted stack area.
* corrected my merge error
* missed a blank
Otherwise interrupts with a logical priority lower than configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY are masked after the first call to xTaskResumeAll() (after the first critical section is entered, and never released).