Update: Unicode related specification adjustments, also perform minor fixes and cleanups.

Update: Unicode related specification adjustments, also perform minor fixes and cleanups.

The Unicode includes some characters that violate some of the expectations of the FSS and IKI standards.

To that end, provide non-strict modes to allow for the FLL based adjustments of these standards.

There are some vertical line like characters that act as punctuation connectors.
Because they connect vertically instead of horizontally, they violate part of the inteded design of FSS and IKI where everything is on a per-line basis.
These Unicode vertical line like punctuation connectors are not to be considered punctuation connectors for the purposes of FSS and IKI processing.

There are some non-printing characters, such as invisible plus.
This is a punctuation character that is also a zero-width character.
For the purposes of FSS and IKI, these characters must not be considered punctuation characters.

Any other zero-width characters are to be considered zero-width and are not to be used for syntax and similar.
(Combining characters are a different beast to be addessed at a later time.)

Further clarify how certain Unicode characters are to be handled, in general.

Unicode dash characters are now being limited in being interpreted as a dash for the purposes of connecting words.
To this end, only the Unicode hpyhens are the allowed dash-like characters (with the ASCII dash being allowed as well for that matter).

Use const where possible.

Fix some wording in some documentation comments.