v0.11.4

Description

• Change Raspbian version to 2018-06-27
• Add Butterfly web terminal
• Add experimental optical flow nodelet
• Add camera visualisation markers node
• Add interactive markers control node
• New default configuration for UART
• selfcheck.py: add boot time checking and CPU usage checking
• Add some plugins to mavros blacklist
• image: add compressed_image_transport plugin
• mavros: sane settings for rangefinders
• Remove FPV camera from clever.launch as it is not used
• image: update web_video_server version
• image: set up syntax highlighting in vim for .launch files
• Deny byobu to check updates and take 100% CPU
• Bug fixes and optimizations