Adds a new rake task `plugin:checkout_compatible_all` and
`plugin:checkout_compatible[plugin-name]` that check out compatible plugin
versions.
Supports a .discourse-compatibility file in the root of plugins and themes that
list out a plugin's compatibility with certain discourse versions:
eg: .discourse-compatibility
```
2.5.0.beta6: some-git-hash
2.4.4.beta4: some-git-tag
2.2.0: git-reference
```
This ensures older Discourse installs are able to find and install older
versions of plugins without intervention, through the manifest only.
It iterates through the versions in descending order. If the current Discourse
version matches an item in the manifest, it checks out the listed plugin target.
If the Discourse version is greater than an item in the manifest, it checks out
the next highest version listed in the manifest.
If no versions match, it makes no change.
This is mostly useful while developing a plugin, to avoid manual actions of deleting tables and schema_migrations rows.
Usage:
bundle exec rake plugin:migrate:down[discourse-calendar]
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
* Allow running specific plugin tests using ENV variables
* Add a `rake plugin:qunit` task to match the existing `rake plugin:spec` task
* Improve docker.rake to allow running specific plugin qunit tests
* Purge cache before and after qunit tests
* Stop module auto-loader trying to auto-load tests
* Use URL query parameters to pass config into Qunit, avoiding caching issues
* Oops, searchParams doesn’t work in phantomJS. Parse the URL manually.
* Escape ampersands before passing URL to phantomJS, otherwise multiple parameters go wrong
