[Hackage] #14: allow preprocessing for Main modules

[Hackage]

#14: allow preprocessing for Main modules
---------------------+------------------------------------------------------
  Reporter:  ijones  |        Owner:  duncan   
      Type:  defect  |       Status:  assigned 
  Priority:  high    |    Milestone:  Cabal-1.2
 Component:  Cabal   |      Version:  1.1.3    
  Severity:  normal  |   Resolution:           
  Keywords:          |   Difficulty:  easy     
Ghcversion:  6.2.1   |     Platform:  Linux    
---------------------+------------------------------------------------------
Changes (by duncan):

  * ghcversion:  => 6.2.1
  * platform:  => Linux
  * status:  new => assigned
  * owner:  ijones => duncan

Comment:

 This second patch has been committed to Cabal HEAD. Perhaps someone can
 test and confirm this as I've only tested one small example.

 One actually needs to say:

 {{{
 Executable: Foo
 Main-is: Main.hs
 }}}

 and it'll look for any suitable file that can be pre-processed into
 {{{Main.hs}}}, like {{{Main.hsc}}} for example.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/14>
Hackage <http://example.com/>
My example project