PX4/NuttX branch test: master

NuttX:
 - https://github.com/PX4-NuttX/nuttx/tree/master
 - PX4/NuttX@43dfbdb

Changes from PX4/NuttX (PX4/NuttX@fdf1837) in current PX4/master (993755b)
PX4/NuttX@fdf1837...43dfbdb

43dfbdb (HEAD, origin/master) Battery monitor support (#404)
922e67c MCP9844 shutdown mode support (#403)
cbd3e70 formatting comments
6b4f903 fix for SAMA5D2 serial console
8c00e43 arch/z80/src/ez80:  Fix eZ80F92 Interrupt Controller
774bd6f Merge branch 'pr396'
09d659d xtensa: Fix up_schedule_sigaction
34b17ec xtensa: Fix up_schedule_sigaction
119a38c xtensa: Fix typos and comments
5f41c94 boards: stm32f4discovery: Remove CONFIG_NET_LOCAL=y from wifi/defconfig

Apps:
 - https://github.com/PX4/NuttX-apps/tree/master
 - PX4/NuttX-apps@127fe11

Changes from PX4/NuttX-apps (PX4/NuttX-apps@91b6ad6) in current PX4/master (993755b)
PX4/NuttX-apps@91b6ad6...127fe11

127fe118 (HEAD -> master, origin/master) telnet: Fix compile error by commit 39bf19d
102d7670 testing: ostest: Add workaround for SMP in cond.c
39bf19d1 Fix some wrong state handler in _negotiate
5f273b2c nshlib: cmd_nfsmount support the mount with TCP protocol
26a5fb0e nshlib: cmd_nfsmount support the mount through domain name
11fedb6b nshlib: cmd_nfsmount should try IPv6 then IPv4 if dual stack is enabled
404b330c Ensure "build" before "install"
4c4d8b1c examples/elf: update elf_main.c dependency to fix parallel build break
52ad01f0 netutils: save wapi config to file system
86bfe133 net/bringup: late net init after nsh script done