* packager: call callbacks consistently
Before this, the callbacks would not being called, which would lead to
an incomplete build on non-OS X platforms when trying to build all for
all platforms.
* packager: Always produce OS X update file regardless of --package option
This makes it consistent with how the windows build always produces the
.nupkg autoupdate files
* packager: fix duplicate npm install
Move "npm prune && npm dedupe" into the release script. Remove an extra
"npm install"
* Make Windows portable app
When a folder named "Portable Settings" exists in same folder as
WebTorrent.exe, then use it instead of the default application config
path.
Closes#358
* packager: remove redundant signing warning
* cross platform zip function
* Set config file path to match config.CONFIG_PATH
* portable app: make electron settings portable
* portable: fix poster/torrent paths
* use cross-zip
* portable app: default download folder inside 'Portable Settings'
