[Processor tool] Add the "comprehensive" CSS class name retrieval mode

[Vincent Cantin]

This mode collects anything that look like it could be a CSS class name, including:

• All the strings
• All the keywords whose name matches the structure of a hiccup tag, regardless of where they are in the source code.

This way to collect the class names will create a lot of false positives, but it will be mitigated by the fact that:

• only the names which are matching the grammar will be kept,
• generating CSS for a few unused class names won't be a big issue in most cases.

This mode is suitable for users working on prototypes and users not having a serious need for having the smallest possible CSS file.