Fix an issue where plugin associations would be mishandled.

When joining plugin models together, I ran into an issue when using
`hasMany('Plugin.Model')`. The SQL conditions would be incorrectly
generated as `Plugin.Model.foo_id` instead of `Model.foo_id`.
Fix failure caused by extra plugin classes being added.
Add missing sprintf in shell.php

One sprintf was missed in the removal of translation methods from the shell.
Merge pull request #4177 from dakota/patch-6

Add missing sprintf in shell.php
Merge pull request #4176 from cakephp/plugin-association

3.0 Fix an issue where plugin associations would be mishandled.
Fixes #4178
remove old css

remove all the code coverage classes has proposed in cakephp/app@d6fbb40d3c55792d27b62a9254a59f165fe4ffa1
Merge pull request #4179 from antograssiot/3.0

remove css from web test runner
Don't call format() to build attributes.

This is just waste. I've yet to see any real reason to allow attribute
formatting to be templatable. Cutting this out saves numerous calls to
format() which can pile up and be expensive.
Add persistent caching to StringTemplate.

This in theory will remove the overhead around compiling templates on
each request.
Remove persistent cache.

It didn't actually increase performance at all. In some cases it would
slow things down as the filesystem was used.