Fix line height for authors on PDF title page

[fingolfin]

UPDATE: the spacing issues in title and subtitle were fixed by @frankluebeck in 5122d04 by different means (adding extra empty lines).

But for the spacing of author names, that doesn't seem appealing to me, the distance is too wide. I initially tried to use \par as describe below but that resulted in LaTeX warnings. Finally Codex found a working solution, which is no in this PR:

Use \strut around author names on the title page so multi-author
blocks get a more suitable line height in the PDF output.

Old text follows:

---

... due to insufficient line spacing. The lines look "smushed together".

See also https://tex.stackexchange.com/a/183710/1755 for an explanation of the changes in this fix.

Before:

After:

[fingolfin]

Alas, while it works in Alnuth, it produces TeX errors in anupq:

[Loading MPS to PDF converter (version 2006.09.02).] ) (./ANUPQ.out) (./ANUPQ.out) ! LaTeX Error: There's no line here to end. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.93 ...intitlesize \textbf{ ANUPQ \mbox{}}\par}\\ ? 

Still, I would hope a variant of this can be made which satisfies both use cases. Any thoughts, @frankluebeck ?

[frankluebeck]

I don't have the input for the example above but made some experiments with another package.

For me long titles and subtitles look fine after this commit.

The problem with ANUPQ seems to come from AutoDoc. The names of the authors in the XML for the title page are followed by a strange <Alt Only="LaTeX"><Br/></Alt> which I think should be removed.

[fingolfin]

I think (but don't remember) that <Alt Only="LaTeX"><Br/></Alt> was added a decade ago or so by Sebastian Gutsche as a workaround for spacing in author lists --similar to the spacing problem that you fixed in 5122d04

This is the Digraphs manual front page without that AutoDoc hack (the vertical spacing between authors is too tight):

And that it is with the hack (the vertical spacing is too big):

(CC @james-d-mitchell as he might have other stylistic preferences ;-) ).

But I agree, this hack should be removed from AutoDoc (I'll do it). In return it'd be great if you could apply a similar fix for the authors as you did for title & subtitle

[james-d-mitchell]

I'm happy with your preferences @fingolfin (at least in this regard :))

[fingolfin]

Found a fix with help by Codex, now in this PR. The Digraphs title page now looks like this (with the patch in this PR, plus a patch to AutoDoc as discussed above, to be included in its next release):