Data.Text for parsec3

[Kazu Yamamoto ( 山本和彦 )]

Hello,

> I think,
> 
>   cabal install --reinstall -O2 parsec3-1.0.0.3
> 
> should repair this.

I made a tiny benchmark using progression and criterion. 

	https://github.com/kazu-yamamoto/parser-benchmark

When I re-install parsec3 with the -O2 option, performance of the tree
becomes almost the same.

	http://www.mew.org/~kazu/plot.png

Note that the input file is ASCII. If we use a UTF-8 file, Lazy Text
becomes much slower. But this is inevitable, I guess.

If people want to compare String and Lazy Text on UTF-8, I will add
the case. If people want to campare attoparsecs also, I will add them,
too.

--Kazu