v2.0.0-pre.14

This release separates the async and sync version of Pageloader for Dart into two separate pub packages. The async version will stay in the pageloader package, while the sync version moved to the new sync_pageloader package. This cleans up the dependencies (async Pageloader doesn't need to depend on sync_webdriver, etc) and makes it easier to deprecate sync Pageloader.

This release contains no functional change. However, if you are using the sync version, you need to update your dependencies to point to the new sync_pageloader package.