PX4-NuttX/nuttx branch test: px4-master_auto_rebase

NuttX:
 - https://github.com/PX4-NuttX/nuttx/tree/px4-master_auto_rebase
 - PX4/NuttX@6de9126

Changes from PX4-NuttX/nuttx (PX4/NuttX@d5c12b2) in current PX4/master (33f7318)
PX4/NuttX@d5c12b2...6de9126

6de9126 (HEAD, origin/px4-master_auto_rebase) [PX4: WIP] Fix transmission status handling in the serial interrupt
e992f27 [PX4: REJECTED] cstdint fix
4b7234d [PX4: REJECTED] add math.h
45626aa [PX4: WIP] Jenkinsfile
0eff3d5 (origin/master) Merged in jutava/nuttx (pull request #673)
8271f72 Merged in raiden00/nuttx_h7 (pull request #672)
0aa30eb include/nuttx/fs/hostfs.h:  Update duplicated definitions in HOSTFS that must match NuttX values.
947c10e tools/mkexport.sh:  Save the User.map file in the export package if available.
283b73e Fix lots of typos in C comments and Kconfig help text
1783d34 Eliminate some new warnings found in build testing.

Apps:
 - https://github.com/PX4-NuttX/apps/tree/px4-master_auto_rebase
 - PX4/NuttX-apps@94741ff

Changes from PX4-NuttX/apps (PX4/NuttX-apps@36806ba) in current PX4/master (33f7318)
PX4/NuttX-apps@36806ba...94741ff

94741ff (HEAD -> px4-master_auto_rebase, origin/px4-master_auto_rebase) [REJECTED] add-var-expansion-in-nsh-parse.patch
db9c56e (origin/master) apps/examples/powerled:  Eliminate a warning about an uninitialized variable.
e66470d Merged in raiden00/apps (pull request #143)
db77b1e apps/examples/tcpblaster:  Fix an error in time calculation.
19b8a52 apps/examples/tcpblaster/tcpblaster_server.c:  Start time was not being initialized on the server side on the first pass through loop so the first output record had a crazy time.
749eccb Squashed commit of the following:
4d8b8fa apps/netutils/dhcpc:  Activates BINDTODEVICE if available, and break up some long lines
0abe341 Merged in raiden00/apps (pull request #142)
3403b1b apps/nshlib/README.txt:  Clarify arguments to the mkrd command.
abcb66c Remove apps/interpreters/micropthon.  There are several reasons for this.  (1) the current version 1.3.8 is very old and no one is supporting it.  (2) the port only includes the core micropython logic and none of the Python libraries.  As such it is useless in any real application.  (3) There have recently been compile failures reported.  It looks like this is due to changes in newlib based toolchains that now bring in incompatible newlib header files.  See issue 104 at https://bitbucket.org/nuttx/nuttx/issues/104/build-micropython-138-error.  With no one dedicated to the support of micropython, it can no longer be carried in the NuttX apps/ repository.