PX4-NuttX/nuttx branch test: px4-master_auto_rebase

NuttX:
 - https://github.com/PX4-NuttX/nuttx/tree/px4-master_auto_rebase
 - PX4/NuttX@4ca03f2

Changes from PX4-NuttX/nuttx (PX4/NuttX@8957a02) in current PX4/master (4f937a2)
PX4/NuttX@8957a02...4ca03f2

4ca03f2 (HEAD, origin/px4-master_auto_rebase) [PX4: WIP] Fix transmission status handling in the serial interrupt
d2132b8 [PX4: REJECTED] cstdint fix
10c31aa [PX4: REJECTED] add math.h
bcc3693 [PX4: WIP] Jenkinsfile
f090bbb (origin/master) syscall/:  Add support for getpeername() and get_sockname() system calls.
e840038 net/ and include/nuttx/net: Add getpeername() support
a1cddfb Update READMEs
4bc2ba3 Merged in masayuki2009/nuttx.nuttx/lc823450_spi_flash (pull request #687)
4c756e3 Update a README
b1daa22 net/udp/udp_finddev.c:  Fix for network byte-order issue when checking if an address is a multicast address.

Apps:
 - https://github.com/PX4-NuttX/apps/tree/px4-master_auto_rebase
 - PX4/NuttX-apps@9318f0e

Changes from PX4-NuttX/apps (PX4/NuttX-apps@36806ba) in current PX4/master (4f937a2)
PX4/NuttX-apps@36806ba...9318f0e

9318f0e (HEAD -> px4-master_auto_rebase, origin/px4-master_auto_rebase) [REJECTED] add-var-expansion-in-nsh-parse.patch
1030ea7 (origin/master) Merged in masayuki2009/nuttx.apps/fix_mksymtab (pull request #147)
cb9e951 apps/Make.defs:  Improve the symtab target.  tools/mksymtab.sh:  Fix a typo.
296f583 apps/tools:  Forgot to include a file with last commit.
272bdc0 apps Makesystem:  Fix an error when building apps/ withtout nuttx/, using only the NuttX export package only and assuming that the nuttx/ directory in not even present.  In this case, the problem fixed where the apps/Make.defs file was selecting tools from the /tools directory which does not exist because TOPDIR=apps/import.  Instead, for this build case, I have not thought of any option but to duplicate scripts as necessary in the apps/tools directory.  Also added a top-level target to compile the symbol table.  Misc fixes: quoting in scripts, some errors in script syntax.
9240ef5 Merged in masayuki2009/nuttx.apps/fix_symtab_related (pull request #146)
4db29bc apps/examples/elf:  Correct some Kconfig coments.
2ecc94f apps/import/Makefile:  Eliminate a MAKE sytax error that occurs in some (but not environments) when symtab.c has not been generated.
878fa8a Squashed commit of the following:
aea8d94 apps/examples/nsh:  The symbol table name and size variale names can now be configured.