configs/.gitignore:  Make sure that any .gdbinit, .project, or .cproject files are ignore so that they are less likely to be included in a patch or PR.

Update tools/configure.c to same functionality as configure.sh.  Add an array of optional file names.  Currently, .gdbinit is the only optional file but other things like IDE-specific project files might need to be copied as well.

Improve configure.sh behavior (proposal).

Approved-by: Gregory Nutt <gnutt@nuttx.org>

 - enable to call from top directory.
 - enable to designate direct path for config.
 - install .gdbinit if the target has.

Fixed typo "CORTEXR5F" in arch/arm/Kconfig

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Fixed ARMv7-M Toolchain definition for Cortex-M4.

Approved-by: Gregory Nutt <gnutt@nuttx.org>

 - Cortex-M4 only have Single Precision FPU.

multiple fixes for stm32f1xx RTC clock

Approved-by: Gregory Nutt <gnutt@nuttx.org>

- compile issues because of missing RTC_MAGIC #defines
- missing functionality based on RTC_MAGIC in RTC based on stm32_rtcounter.c
- IRQ setup from up_rtc_initialize was later reset in up_irqinitialize
- write access to backup registers without enabling access to backup domain
- possible races in set/cancel alarm
tested with STM32F103C8 only
device now wakes up from forced STANDBY mode by alarm

pthreads:  Move pthread_barrier_init, pthread_barrier_destroy, and pthread_barrier_wait from sched/pthreads to libc/pthreads.  This just coordinate other OS interface calls but are not a fundamental OS interfaces and, hence, do not belong within the OS.

pthreads:  Move pthread_cond_init and pthread_cond_destory from sched/pthreads to libc/pthreads.  This just coordinate other OS interface calls but are not a fundamental OS interfaces and, hence, do not belong within the OS.

pthreads:  Move pthread_once from sched/pthreads to libc/pthreads.  pthread_once just coordinates other OS interface calls but is not a fundamental OS interface and, hence, does not belong within the OS.

pthreads:  Move pthread_yield from sched/pthreads to libc/pthreads.  it is a simple wrapper for sched_yield and does not belong within the OS.

Upstream kinetis

Approved-by: Gregory Nutt <gnutt@nuttx.org>

   Initalize SPI1 on connector J6. No real use, as of yet.

testbuild:Added -x to fail build on errors for CI

Approved-by: Gregory Nutt <gnutt@nuttx.org>

   On CI we want to know ASAP of a failure. This adds the
   -x (exit on build failures) option to faclitate that
   behavior.

   Use ${MAKE} ${MAKE_FLAGS} for make invocation.
   When -x is provided change MAKE_FLAGS to
   --silent --no-print-directory and set -e

   Ignore exit status when using grep for checking
   for CONFIG_NXWM=y

mtd/w25: wait for BUSY flag to clear in w25_readid and w25_unprotect.  W25Q128 datasheet says that all instructions expect 'Read Status Register' and 'Erase/Program Suspend' are ignored when BUSY flag in status register is '1'. Therefore wait for busy flag to clear in w25_readid() and w25_unprotect().

stm32/stm32l4 PWM: While attempting to output a 70 MHz square wave from the timer output of a STM32 clocked at 140 MHz (which works fine in baremetal C), I stumbled on what I believe to be an error in arch/arm/src/stm32/stm32_pwm.c.  Line 1304 we are told that

reload = timclk / info->frequency;

which I belive to be incorrect, it should be

reload = timclk / info->frequency - 1;

since starting to count from 0, if I want to output half of the TIM clock, I must count to 1 and not to 2.

Surely enough, the original code did output 140/3=47 MHz, while this correction does allow the output up to 70 MHz.

I am not sure this affects most users generating slow PWM (e.g. PX4) but for frequencies
close to the PCLK, indeed the difference becomes significant.

stm32_hrtim: GPIOs configuration + EEV and FAULT strucutres

Approved-by: Gregory Nutt <gnutt@nuttx.org>

MTD M2PX: If we READ while a write/erase is pending, the command is ignored and the write/erase continues. If we dont catch this situation we will return garbage to the user because the flash will not execute the command.  So READ MUST wait for write completion, and before that, the bus must be locked since it's a precondition to calling waitwritecomplete().