Dashes and underscores in id and class attributes

[akamaus]

Hi, thanks for the package!

I've found what it refuses to parse many real world tags because your lexer is too strict. Take a look at http://www.w3.org/TR/CSS21/grammar.html

I made a quick fix for supporting dashes and underscores in id and class attributes.

[mkrauskopf]

Similarly for tag names which I've fixed with:

diff --git a/Text/CSS/Parser.hs b/Text/CSS/Parser.hs
index 5c6c775..2abd0c7 100644
--- a/Text/CSS/Parser.hs
+++ b/Text/CSS/Parser.hs
@@ -42,7 +42,7 @@ nmchar  = alphaNum <|> oneOf "_-"

 -- | selects a tag name, like @ h1 @
 typeSelector :: ParsecT [Char] u I.Identity [Char]
-typeSelector = many1 alphaNum
+typeSelector = many1 (alphaNum <|> oneOf "_-")

 -- | universal selector, selects @ * @
 universalSelector :: ParsecT [Char] u I.Identity String

Forking just for this seems to me as overkill. So attaching to this related issue. Hopefully OK.

[egonSchiele]

Thanks!