po4a chokes on images + text in tables

[StefanBruens]

Po4a has isses when processing the "eeschema_simulator.adoc", the table with the "image::images/opamp_symbol.png"

The following minimal example shows the issue:

|====
|First col
|Second col

image::foo.png[alt="Alt"]

Text below image 1
|====

image::foo.png[alt="Alt"]

Text below image 2

After processing with po4a, e.g. po4a-normalize -f asciidoc test.adoc, this ends up as

|====
|First col
|Second col

image::foo.png[alt="Alt"]
  Text below image 1
|====

image::foo.png[alt="Alt"]

Text below image 2

i.e. "Text below image 1" becomes "verbatim" text in asciidoc.

This has the strange side effect of creating a " in docbook, which is converted to a "/fvlisting" (fancyverb) in latex. Xelatex processes this using a temporary file, and chokes reading it back (/VerbatimInput) when it contains UTF-8 multibyte sequences starting with e.g. <0xC4> or <0xC5> (<0xC3> is fine).

This is an issue e.g. for Polish, see also #635