Always extract styles/classes/attrs required by ACRs before creating filter.allowedContent array to unify its format

[Piotrek Koszuliński]

Now:

• some ACRs available in filter.allowedContent array have styles/classes/attrs required by them only marked with "!" characters.
• some have their required styles/classes/attrs copied to requiredClasses/Styles/Attributes arrays.

We should always expose the second format.

[Wim Leers]

I reported this while working on ​http://drupal.org/node/1894644.

[Piotrek Koszuliński]

Pushed ​t/10191 on dev and tests.

I thought that this patch will be pretty simple, but it isn't :)

• All added rules are now pushed to filter.allowedContent in standardized format. All kinds of elements/styles/classes/attrs validators are transformed to objects like:

{ foo: true, bar: true }.

I chose objects rather than arrays because in the future we may need to add values validators (styles values and attributes values) and then objects will be the only solution to keep both - names and values.

• I removed support for function and regexp based validators, since they were not used anywhere and aren't serializable (so they cannot be easily reused on e.g. PHP side). Instead, we may want to introduce string validators with wildcards, e.g.: attributes: 'data-*'. Extracted to: #10202.

[Piotrek Koszuliński]

Fixed on major with ​git:97b4f24 on dev and c7b659d on tests.