Update to 0.12.8

CHANGES:
0.12.8
    #560, space leak (fixed)
0.12.7
    Allow deepseq-1.3
    Allow QuickCheck-2.5
    Support bytestring-0.10 (NFData instances added)
0.12.6
    #515, don't crash on malformed characters (use ? instead)
0.12.5
    Add optRawTag to Render, to ensure script's don't get escaped
0.12.4
    #487, fix the behaviour of ~== for TagComment and others
0.12.3
    GHC 7.2 compatibility
0.12.2
    Add StringLike instances for Text
0.12.1
    Add parseOptionsEntities and improve documentation
0.12
    Upgrade to QuickCheck 2.4.*
    Export toTagRep
    Make the -download flag off by default
    Eliminate HTTP dependency
    Eliminate mtl dependency
0.11.1
    Support --flags=-download to eliminate the network dependency
0.11
    #326, <a "foo"> is no longer treated as an attribute
    Add Eq/Ord instances to Tree
    Don't mark Text.HTML.TagSoup.Tree as preliminary
    #325, \r should be treated as whitespace
0.10.1
    #322, don't change ' to &apos; in render (do what the docs say)
0.10
    Improve the cabal file, make the test program off by default
    Expose Text.HTML.TagSoup.Match again (was hidden accidentally)
0.9
    #294, let optEntityData see if there was a ';' (CHANGES API)
    Numeric/hex entities in attributes were misparsed
    #149, add escapeHTML function