patch applied (packages/pretty): Added instance Monoid Doc where mempty = empty; mappend = (<>)

[Ian Lynagh]

Fri Oct  8 00:23:58 PDT 2010  Bas van Dijk <v.dijk.bas at gmail.com>
  * Added instance Monoid Doc where mempty = empty; mappend = (<>)

    M ./Text/PrettyPrint/HughesPJ.hs +5

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=packages/pretty;a=darcs_commitdiff;h=20101008072358-ae560-fd26dc207733c6232cfbb3769c1176ac9a70c82b.gz