osjs-2.0.0-93

Mostly bugfixes, but also added the '--optimization' build flag and changed
package layout so server files are in a dedicated 'server' directory.

If you want to use the new directory feature, use the 'main' setting in
your package metadata file (see included).

Related: http://community.os.js.org/t/update-version-bump-alpha93/128

• Preview: Added error message when opening location without mime
• Settings: Added some exception handling to certain async events
• CoreWM: Prevent an error in weather panel item when destroyed
• VFS: Fixed creation of empty files
• GUI: Improved error handler in drop event
• connection: Added 'offline' and 'online' event
• server-node: Added some signals on instance start/stop
• server-node: Updates to 'sane' shutdown
• server-node: Prevent falsy error message when loading modules
• server: Support custom main server file via manifest
• build: Remove 'server' files automatically from dist packages
• build: Added optimization option to build
• misc: Updated package.json dependencies
• misc: Some linting, fixed broken icons
• misc: Packages now have dedicated 'server' folder for server-side code