* Cygwin: repaired NuttX build after 1f63d858
all the NuttX specific WINTOOL define handling was skiped in cmake Make.defs generation
The Nuttx build is makfile based and needs its cygwin treatment

Additionally the ${PX4_SOURCE_DIR}/src/include which was added through cmake needs path conversion

The two root causes for the special handling are:
- ARM GCC for Windows doesn't support cygwin paths passed as an argument
  so they need to be either relative or converted via cypath tool
- Symbolic links are totally different under Windows and because NuttX uses them extensively
  it has special handling scripts that need to be fed with the correct defines

* Cygwin: NuttX include paths all converted in Make.defs.in

differentiate between WINTOOL define (MSYS & cygwin) and cygwin using uname command:
- MSYS needs symbolic link handling for ARM GCC but no path conversion
- Cygwin needs both

This is a temporary workaround for equal expressions in chip/sam_xdmac.c
and can be reverted once fixed properly in NuttX. Needed for the GCC 7
upgrade in #8551.

because the relative path is interpreted differently on linux, mac and windows

Most of the incompatitbilities are luckily similar to the darwin build.
- New target OS __PX4_CYGWIN added because in other build environments on Windows defines will very likely be completely different
- added all necessary exeptions to the defines
- disabled priorities completely because on Windows they are defined 1-32 and with all the arbitrary +40 -40 priority settings there were a lot of problems
  not only did some threads/"virtual tasks" not start because of out of bound priorities but also the resulting scheduling was totally random and inadequate
  with default priorities it ran toally fine during my first tests, should be rethought when windows is used onboard in the future

https://github.com/PX4-NuttX/nuttx/pull/7

 - this works around cygwin path issues on windows

There was and extra "nuttx" dir:
	cp: cannot stat '/home/lucas/p/dronecode/PX4/Firmware/build/aerofc-v1_default/NuttX/nuttx/nuttx/.config': No such file or directory
	FAILED: NuttX/CMakeFiles/menuconfig

And the board fixup being executed from the wrong working directory:
	nuttx-configs/aerofc-v1/nsh/defconfig
	fatal: Path 'nuttx-configs/aerofc-v1/nsh/defconfig' does not exist in 'HEAD'

   Tied to nuttx, apps  px4_firmware_nuttx-master
     rebased on upstream nuttx master @ 3647ace55958c094cfe93f07092d308a768f5ca3
     rebased on upstream apps master @ 21c9b793e2ca6f4e86388c80d7af5c466de5e71c

   Latest nuttx 7.22+ with PX4 contrib for stm32 f4 I2C hang.

  Prep for Nuttx Upgrade - still needs i2c fix

  Updated to latest upstream with PX4 contrib for STM32 I2C that
  fixes an hang in driver.

* NuttX cmake

* px4_macros:Pass the stringified predicate as second arg to static assert

   CC_ASSERT mapes to the c++ static_assert or provides the same
   funtionality for c via the other macros. The c++ static assert
   takes 2 argumants the prdicate and a message. This fixes the
   lacking second argument.

* Updated nuttx and apps submodule to upstream nuttx 7.21+==master

   This is the latest uptake of upstream nuttx and apps.

* ROMFS generate with xxd instead of objcopy

* delete nuttx-patches

* NuttX update submodules to latest px4_nuttx-master

* fix nuttx apps and board dependency

* docker_run update to latest container 2017-08-29

* cmake ROMFS portable sed usage

* NuttX update submodules to latest px4_nuttx-master