Use "\samp{...}" instead of "``\code{...}''" when showing markup fragments

Use "\samp{...}" instead of "``\code{...}''" when showing markup fragments
in the running text.

For computed method names (where there's a \var{} part to the name), use
the non-indexing form of \funcdesc{}.  This doesn't change the printed
output, but removes 3 rejections from the makeindex run and allows the
LaTeX2HTML support to exclude these from the index.