Backport (#283)

* Develop (#265)


* Patch for file dialog on OSX

* Update CONTRIBUTORS.md

* 262 add wails shutdown method (#264)

* feat: support close in bridge mode

* feat: WailsShutdown callback

Now handles proper shutdown through:
  * runtime.Window.Close()
  * Killing the main window
  * Ctrl-C

* chore: version bump

* chore: version bump

* feat: adjust binary name for OS

* fix: allow spaces in gcc path

* feat: migrate command

* fix: npm/node versions

* fix: allow IE for serve

* feat: go build script

* fix: make runtime ES2015 compliant

* fix: remove invoke patch

* fix: allow any line endings

* chore: remove legacy bridge files

* chore: latest assets

CONTRIBUTORS.md

@@ -20,4 +20,3 @@ Wails is what it is because of the time and effort given by these great people.
 * [Toyam Cox](https://github.com/Vaelatern)
 * [Robin Eklind](https://github.com/mewmew)
 * [Kris Raney](https://github.com/kraney)
-* [soon cheol shin](https://github.com/scshin0572)