ligature marks over letters need to be made smaller

[jbodel]

Current marks extend over three letters when only 2 are in ligature. There ARE cases of 3- and 4-letter ligatures, so we need to be clear about how many letters we mark as in ligature. CIL convention was to expand or shrink the size of the mark to encompass the number of letters included. P-K conventions use marks over individual letters to indicate a ligature with the following letter. So, a 3-letter ligature would be indicated by two letters in a row with ligature marks above.

The latter method seems preferable because more clear semantically although less clear visually.

[sdigiulio]

This is probably pegged to the font-set we're using in display (@emylonas correct me if I'm wrong on this, though); we can potentially make an adjustment in the CSS that would alter the appearance, but it would affect all text, not just the ligature marks themselves.

In terms of how to display across more than 2 characters, the current EpiDoc stylesheets follow P-K, so that's what we should be using currently in those situations. If it's not, then something has gone awry in the stylesheets themselves.

[sdigiulio]

We'll open an EpiDoc ticket for this, since much of this is handled in the default EpiDoc style sheets and is likely a problem that extends beyond our project.