Create quirks mode sample

[Alfonso Martínez de Lizarrondo]

As long as quirks mode is supported a sample should be added, at least in the development builds, so it's possible to easily check features/bugs without the need to change the code of the samples themselves.

This means also that checking for regressions in the CKEditor equivalent of ​http://rev.fckeditor.net/ can be done easily just testing the appropriate sample online.

Also other kind of features that are supported should have a test file for the same reason, as it's easier to say "check sample xxx and do that" instead of "modify sample xxx in this way and do that" (multiple editors, RTL, relative/absolute position...)

[Frederico Caldeira Knabben]

Milestone CKEditor 3.x deleted

[Piotrek Koszuliński]

It's not something we need any more. QM is pretty much gone and we have bug reports related to it very rarely. But first of all - it would be a bad PR.