Introduce the ability to navigate using an anchor and aim.
Example use: Set spacecraft as anchor and planet as aim to always look down at a planet, while followin the spacecraft in its orbit.
* Add Adam Aslegård's module that renders Gaia mission stars
* Add module for Gaia mission
* Add CCfits and cfitsio submodules and the implemented fitsfilereader module from the OpenSpace-sun-earth-event branch
* Add a TaskRunner to read from a fits file
* Adding ability to render other data values from Star speck files
* Add new method to OptionProperty to take vector of options
* Make it possible to change the speck file at runtime
* Include viridis color lut
* Add Apogee and Galah datasets
* Make it possible to filter stars by other data values
* Add ability to statically filter data values
* Update node packages, download nodejs in build process, start server from openspace process
* Patch CEF cmake automatically
* Build webserver automatically
* Work on CMake for WebBrowser, Webgui and CefWebGui
* Map key modifiers to CEF
* Smooth time interpolation in webgui
* Automatically focus on search field in filter lists
* Move webgui code to external repositories
* Use asset system to distribute webgui
* Remove webgui from main repository
* Add support for right click in webgui and improve timetopic
* Resolve cmake policy warning
* Add relative time interpolation to lua interface
* Sanitize json error message before logging error. Workaround for #736
* Added gui properties to scene graph nodes
* Add version topic
* Add shortcuttopic
* Add ability to disable rendering of cefwebgui
* Don't do message loop work if there is no browser.
* Set correct path to nodejs on unix
* Message loop work in presync
* modifications for shortcuts in gui, added names for shortcuts
* Set properties via lua scripts
* Allow gui grouping for shortcuts
* Add gui paths keybindings
* Blocking keyboard callbacks when webgui has keyboard focus in an editable field
* Allow disabling of WebBrowser and CefWebGui
* Make it possible to hide GUI
* Get rid of redundant dashboard items if web gui is used
* Hide WebGUI on slave nodes
* Hide WebGUI on main rendering window if a GUI window exists
* Enable WebGUI on default unless it is overwritten in the openspace.cfg
* Add guiName for propery owners in socket api
