release.sh: build in release mode after testing
release.sh: use HEAD instead of non-existing tag
release.sh: add changelog to release commit
release.sh: make sure releases happen on master in clean repository
Update extension manifest
These are random changes that I hope will fix whatever the chrome web
sotre dislikes about new Firenvim releases.
release.sh: swallow possible git tag --delete error messages
release.sh: prepare list of changes for amo changelog
release.sh: abort if non-package files have been modified by npm
release.sh: don't copy directory structure in chrome.zip
release.sh: run tests, fix .tar.gz generation, open store pages
Usage: `release.sh 0.1.18'
Checks that the version number makes sense and creates the bundles that
need to be uploaded to the chrome/firefox stores.