[GHC] #4196: add more stolen syntax to the user guide

[GHC]

#4196: add more stolen syntax to the user guide
---------------------------------+------------------------------------------
    Reporter:  maeder            |       Owner:               
        Type:  task              |      Status:  new          
    Priority:  normal            |   Component:  Documentation
     Version:  6.12.3            |    Keywords:               
          Os:  Unknown/Multiple  |    Testcase:               
Architecture:  Unknown/Multiple  |     Failure:  None/Unknown 
---------------------------------+------------------------------------------
 language extensions:

 - Bang Patterns disallow an infix funlhs for "!"

 - Magic Hash disallows sections like "(3#)" and infix terms like "3# 1"
 without a space before # (for a user-defined operator "#" or "##")

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4196>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler