* Revert 79d164309f
as it seems to break shortcuts altogether
* Update electron-builder (and add the squirrel windows package
that the newer version now requires: it's been split out). This
uses a newer version of squirrel which has some fixes for
shortcuts.
I'm unsure exactly what was going wrong originally in
https://github.com/vector-im/riot-web/issues/2775 but #79d1643
seems to break shortcut creation as far as I can see.
All of those cpx invocations were getting unwieldy, and I suspect the exotic
quoting needed to run them under parallelshell was breaking things on windows.
Replace the unwieldy cpx invocations with an unwieldy custom script.
which it turns out is by far the lesser of two evils.
* Auto-update works with a proxy
* The update process is reasonably atomic & faster, rather than
running the uninstaller then the installer, leaving you with a
broken install if you shut down your machine at the wrong time
* Gets the update URL the same way as on mac, rather than baking
it into the app at build time from package.json. We don't want
it in package.json because only our builds want our update URL.
Amalgamate the electron build packaging into one script.
Use update_base_url so we can compute the actual URL in the
script for windows (because we need to put it in the build) and
at runtime for mac os.
* Remove squirrel hooks (the installing & uninstalling is now
done by the, er, installer)
* Switch to electron-auto-update
* Shorten initial update delay because we no longer need to wait
for squirrel to release a lock file
* Change update URLs because windows is now one installer for
both 32 & 64 bit.
* Update electron-builder to 10 where NSIS is now the default
target for Windows.
* Add linux to the target list, building a deb.
* Remove sqirrel-specific installation spinner
* Remove redundant !**/* from files
