Updated 6.4 Windows installer RC

[Sigbjorn Finne]

An updated version of the Windows installer for ghc-6.4 is now available
for testing,

  http://www.haskell.org/ghc/dist/stable/dist/ghc-6-4-bld1.msi
  md5 checksum: 4a55a5614587cef07a19d7f7728f3a83

It hopefully sorts out the showstopping profiling problems that people
have reported; let me know if it doesn't and/or there are other packaging
snafus. If nothing major pops up, I'll consider the bits blessed and hook
the installer up to the GHC downloads page.

Note:
  - the installer re-uses the product GUIDs of the original 6.4 installer,
    so if you've already got it installed, it'll remove that install the 
first
    time you run it.
  - the HGL and Win32 packages have been removed from the installer
    at the suggestion of the package author(s); deemed not quite yet ready
    for primetime, I believe.

--sigbjorn