Processing doxygen @param comments for a parameter whose name did not
appear in the function declaration would cause a segfault due to a
null pointer dereference.
Adding test cases for both variadic function (no specified arguments)
and @param comment that references an argument that is not named in
the function prototype. Both of these cases previously segfaulted.
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.
