patch applied (ghc-6.6/ghc): Packages cleanup, and allow new packages to be loaded with :set again

[Ian Lynagh]

Mon Sep 18 18:24:48 PDT 2006  Simon Marlow <simonmar at microsoft.com>
  * Packages cleanup, and allow new packages to be loaded with :set again
  
  This cleans up the package subsystem a little.  There are some
  changes to the GHC API as a result.
  
    - GHC.init and GHC.initFromArgs are no longer necessary.
  
    - GHC.newSession takes the root of the GHC tree as an argument
      (previously passed to GHC.init).
  
    - You *must* do GHC.setSessionDynFlags after GHC.newSession,
      this is what loads the package database.
  
    - Several global vars removed from SysTools
  
    - The :set command in GHCi can now cause new packages to be loaded,
      or can hide/ignore existing packages.

    M ./compiler/ghci/InteractiveUI.hs -19 +17
    M ./compiler/ghci/Linker.lhs -1 +1
    M ./compiler/main/CodeOutput.lhs -1 +1
    M ./compiler/main/DriverPipeline.hs -4 +4
    M ./compiler/main/DynFlags.hs -17 +17
    M ./compiler/main/GHC.hs -43 +26
    M ./compiler/main/Main.hs -17 +19
    M ./compiler/main/Packages.lhs -149 +225
    M ./compiler/main/SysTools.lhs -67 +14