In particular, do not use com.sun.javadoc deprecated since Java 9 and
finally removed in Java 13, to allow the tests to run under modern JRE.
They don't run under Java 8 and earlier any more, but this shouldn't be
a huge problem nowadays and as SWIG output is independent from the Java
version used, it's enough to test it with modern Java versions.
Note that the tests themselves were changed only in the most minimal
way, to adapt them to the new way of running javadoc (which is now also
integrated into CommentParser itself instead of being duplicated in
every test).
Fix how end of paragraph is identified when parsing \code and
\verbatim blocks that appear within a paragraph and contain an empty
line. Previously this would generate a warning for unexpected end of
doxygen comments, and it could generate a segfault due to
dereferencing an invalid iterator value.
The doxygen_basic_translate.i and doxygen_basic_translate_style2.i
tests have been updated to serve as regression tests for this
behavior. Prior to this fix, inclusion of the empty code block line
in this context produced a segfault.
