Fix warnings
Add missing widget
Start of mock FileSever for unit testing
Add new QGCUASFileManager unit test
Mock mavlink ftp server
Mock mavlink plugin support
QGCUASFileManager unit test
List command is now fully working

Also changes for Ack timeouts and unit testing
Fix image packet code

These changes prevent random encapsulated data packets as being thought
to be images.
Error messages to text box
Merge pull request #725 from DonLakeFlyer/mavlink-ftp

Mavlink FTP implementation List command