Put math in HTML inside <span class="math">.

This way it can be distinguished from the surrounding text, e.g. put
in a different font.  Updated README accordingly.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@1130 788f1e2b-df1e-0410-8736-df70ead52e1b

README

@@ -862,7 +862,9 @@ In HTML and S5 output, the way math is rendered will depend on the
 command-line options selected:
 
 1.  The default is to render TeX math as far as possible using unicode
-    characters, as with RTF and Docbook output.
+    characters, as with RTF and Docbook output.  Formulas are put inside
+    a `span` with `class="math"`, so that they may be styled differently
+    from the surrounding text if needed.
 
 2.  If the `--asciimathml` option is used, TeX math will be displayed
     between $ characters, as in LaTeX, and the [ASCIIMathML] script will

Text/Pandoc/Writers/HTML.hs

@@ -411,7 +411,8 @@ inlineToHtml opts inline =
                                GladTeX ->
                                   return $ tag "eq" << str
                                PlainMath -> 
-                                  inlineListToHtml opts (readTeXMath str))
+                                  inlineListToHtml opts (readTeXMath str) >>=
+                                  return . (thespan ! [theclass "math"])) 
     (TeX str)        -> return noHtml
     (HtmlInline str) -> return $ primHtml str 
     (Link [Code str] (src,tit)) | "mailto:" `isPrefixOf` src ->