suggestion: add a .ehs file type

[Simon Marlow]

Alex Jacobson wrote:
> I'm fine with that as well.  I'm just opposed to being force to look up 
> the precise names the compiler happens to use for each language 
> extension I happen to use.  Having -fglasgow-exts turned on by default 
> also works.

-fglasgow-exts is a historical relic.  It's just an arbitrary collection of 
extensions.  It doesn't contain all the extensions provided by GHC, as many 
of them steal syntax and you probably don't want them all on at the same 
time.  We're trying to move away from -fglasgow-exts, which is why GHC 
6.8.1 provides separate flags for all the extensions we provide. 
Eventually we'll have a new standard (Haskell' or whatever) that will 
collect many of the extensions together, so you'll just have to write {-# 
LANGUAGE Haskell' #-}.

Cheers,
	Simon