Remove references to my markdown patch
Add style information
Update examples
Remove output argument for knit2html

it is unnecessary and causes an error
Support using render_html output hook

If markdown uses the render_html output hook, r functions will be wrapped with
a span of class functioncall.  In these cases create a link to a google query
for the function name, searching the ggplot2 and inside-r.org sites for
documentation on the functioninside-r.org sites for documentation on the
function.