If i4neo is build concurrently, then the 'cp' operation in the
Makefile recipe can fould due a time-of-check-vs-time-of-use condition
in 'cp'.

Transcript written on /builds/flow/foo/submodules/i4neo/.latex-cache/beamerthem
eneo.log.
cp: cp: cannot create regular file '/builds/flow/foo/submodules/i4neo/beamercolorthemeneo.sty'cannot create regular file '/builds/flow/foo/submodules/i4neo/beamercolorthemeneo.sty': File exists
: File exists
cp: cannot create regular file '/builds/flow/foo/submodules/i4neo/beamerfontthemeneo.sty': File exists
make[3]: *** [Makefile:43: /builds/flow/foo/submodules/i4neo/beamerfontthemeneo.sty] Error 1
make[3]: *** Deleting file '/builds/flow/foo/submodules/i4neo/beamerfontthemeneo.sty'

That is because 'cp' internally first checks if the file exists, and
if not create it. If the file appears after the first check, then 'cp'
may fail due to EEXIST.

We now use 'flock' to ensure that only one 'cp' is performed at a
time. Note that this also protects the 'latex' invocation with
'flock', since it could suffer from the same problem (however, I did
not observe it there).

bibtex_fudge must be set for latexmk 4.70a (included in Debian Bullseye)
to workaround output directory restrictions in bibtex. see also
https://tex.stackexchange.com/a/564691

The regular font weight had a gigantic difference between normal and fat
text. Whereas for the book font weight there was barely any difference
at all.

Adapted from https://github.com/matze/mtheme/pull/343 by kno10

The special target %_bbb.pdf will address this issue by converting them into paths - which will increase the file size and disable copy & paste of text, however this shouldn't be an issue for presentations and the document is displayed correctly in BigBlueButton.

Currently replaces frametitle icon, if both icon and subtitle are set.

There is no option 'inner/block'.

Fixes font styles 'light' and 'regular', as the required font styles
were renamed upstream.

See the following upstream commits:
https://github.com/mozilla/Fira/commit/317e6c0d9a06c9b9db2a7b1281ccb7e8f983cd98
https://github.com/mozilla/Fira/commit/d6d05bf47955a36aab5d66319882b17b95944d92

Backported from
https://github.com/cebe/pdfpc-latex-notes/commit/c90dd140277e40545a78a8b89df7ae0284a3b224

This reverts commit 1437460b.

Previously the titlepage still got the nWhite background color.

Delete output pdf on build failures

See merge request !2

This is intended as a replacement for the call of the clean target in the
i4neo-demo Makefile. The call of clean is problematic as this triggers
both the clean target in i4neo-demo and the cache in the i4neo theme.

The dependency on the cache dir only serves to ensure that the cache
directory exists. Using a normal dependency, however, causes make to
rerun every dependent task once any file in the directory has changed.
This usually causes lots of unnecessary rebuilds. Fix this by specifying
the cache directory as order-only dependency which avoids rebuilds due
to changed dependencies.

Up to now, the alignment was done using \hfills, which will cause the
shorttitle to be centered between author and pagenumber, but not
centered with regards to the current page.
This commit introduces a tikz overlay instead. Please note: for the
standout-style, the bar has to be drawn twice: This is the only way to
draw the background and text on the main layer, without resorting to
pgfonlayer, which might have the unfortunate result of mixing with
included tikz graphics.