Work on save function and create core module

Add editor_core module
Move fileBrowser to editor core module
Add fileSaveDialog to later use for save function
Edit css file for fileBrowser, directory and file entries now occupy the
whole width of the browser
Move jump.lvlml from source folder to model test directory
Remove Gizmo default light and just use the lights given in lvlml files
Start implementing the Save function of the editor