Set the Composer minimum-stability key to "dev" until we're in RC
Add prefer-stable to extension composer.json

Signed-off-by: Gawain Lynch <gawain.lynch@gmail.com>
Cleaning up / reorganising contenttypes.yml.dist. Working on #1715
Updating bolt.css
fix for issues #1730, added base.scss, added oldie mixin and some minor fixes for ie8
some new files for #1730 ie8 issue
Merge pull request #1737 from GawainLynch/hotfix/composer-pre-rc-minimum-stability

Set the Composer minimum-stability key to "dev" until we're in RC
git push origin masterMerge branch 'sbonardt-feature/issue-1730-backend-IE8'
Merge branch 'master' of github.com:bolt/bolt
Disable UI elements when extensions cannot be managed in backend

It's not perfect, but it'll have to do.
Add meta tag "X-UA-Compatible" for IE.