Rework special keywords

[adya]

Currently NNDTitleless is used for both Title and Obscurity scopes. This poses certain limitation, as original name can be either used in both or none at all. Furthermore, with introduction of separate Title scope a keyword NNDTitleless is confusing (it doesn't affect custom titles).

To solve these issues we're gonna need to:

Streamline keywords naming

• NNDTitleless -> NNDDisableDefaultTitle - a bit more wordy, but makes it perfectly clear on what it does
• NNDExcludedTitleless -> NNDEnableDefaultTitle - now this makes even bigger impact
• NNDExcludedUnique -> NNDNotUnique - this should add a bit more clarity.
• Preserve NNDUnique - this is fine 🙂
• Preserve NNDKnown - this is also fine. Note: Known keyword doesn't need a counterpart like others, because by default everyone who can be obscured will be obscured.

Untie obscurity from NNDTitleless

Create a new pair of keywords similarly to new title keywords, but that will work for obscurity.

• NNDDisableDefaultObscurity
• NNDEnableDefaultObscurity

Backward compatibility

Renamings should automatically happen along with other routines in modernize
Actually, backward compatibility will be embedded using this distr:

Keyword = NNDDisableDefaultTitle|NNDTitleless
Keyword = NNDEnableDefaultTitle|NNDExcludedTitleless
Keyword = NNDNotUnique|NNDExcludedUnique

This should silently distribute new keywords without needed to update all custom made patches.