Ref Man for my contribution

I'll be happy if this could be proofread before I merge ...
I think this gets parsed as `\emph{c}oqlib{\tt /user-contrib/}`.  You probably mean `\textit{coqlib}\textt{/user-contrib}`.  (Since this is italicized not as emphasis, but as a variable, you it's slightly better style to use `\textit` rather than `\emph`.)