js/flight: Added map.hover_enabled flag
js/flight: Added baro.hover_enabled flag
js/flight: Added basic playback functions
js/baro: Added click support

This is not influenced by the hover_enabled flag and can be used
in playback mode
js/flight: Added Start/Stop button
js/flight: Check global_time value explicitly

This makes the playback compatible with the live tracking pages
css/ol-PlayButton: Added z-index

This puts the play button behind the layer switcher
Merge pull request #251 from Turbo87/play

Playback function for flights
fabric: Adding fabric v1.8.2 to developer requirements file
fabric: Added basic fabfile

This requires that the developer has setup a "skylines" host in his
SSH config file (`~/.ssh/config/`)
fabric: Call restart.sh in repo folder directly

.. and do the git reset call
fabric: Moved instructions from restart.sh into the fabfile
fabric: Extracted restart_service() task
fabric: Added push task
fabric: Added deploy task
fabric: Removed unnecessary cd() from restart_service task
fabric: Use sudo() function for db migration call
fabric: Extracted manage task
fabric: Added optional user parameter to manage task
fabric: Extracted WORKING_DIR constant