WIP: Mavlink file server
Implement directory listing
Merge branch 'master' into mavlink-ftp
Added debug printfs
Merge branch 'master' into mavlink-ftp
fix extraction of path info from FTP request
Don't queue empty work items.
Support link forwarding
Added include order warning
MAVLink helper function fixes
Formatting and some ftp drive-by
Fixed threading and transmission issues for FTP
Fix packing of directory entries in the List reply
merged master
mavlink-ftp: Remove two extra bytes we don not need
mavlink-ftp: Remove commented out code
mavlink-ftp: Add extra padding because the ringbuffer implementation relies on its use
Support for List, Open, Read, Terminate commands

Fixed various bugs. Flattened Mavlink::Session class while fixing bugs
in this area.
Merge pull request #1083 from DonLakeFlyer/mavlink-ftp

FTP List, Open, Read, Terminate commands working end to end with QGC
Merge pull request #923 from PX4/mavlink-ftp

Mavlink File Transfer Protocol (FTP)