gc unused imports

- fix copyrights
- remove some unused imports
- comment formatting fixes

Adding in the modified versions of the Standard Haskell 98 libraries.
These should compile under both Hugs and GHC.

use the flags  -D__HUGS__ -DUSE_REPORT_PRELUDE to extract the Hugs src.

../compiler/msg_prel

Fised & improved lexing of escaped numeric character literals + a regression
test.

Changes to make the Prelude comply with Haskell 98.

I claim that this completes GHC's implementation of Haskell 98 (at
least feature-wise, but there's bound to be some bugs lurking..)

Move 4.01 onto the main trunk.

Library re-organisation:

All libraries now live under ghc/lib, which has the following structure:

	ghc/lib/std    		--  all prelude files 		(libHS.a)
	ghc/lib/std/cbits

	ghc/lib/exts		-- standard Hugs/GHC extensions (libHSexts.a)
				-- available with '-fglasgow-exts'

	ghc/lib/posix		-- POSIX library                (libHSposix.a)
	ghc/lib/posix/cbits     -- available with '-syslib posix'

	ghc/lib/misc		-- used to be hslibs/ghc	(libHSmisc.a)
	ghc/lib/misc/cbits	-- available with '-syslib misc'

	ghc/lib/concurrent	-- Concurrent libraries		(libHSconc.a)
				-- available with '-concurrent'

Also, several non-standard prelude modules had their names changed to begin
with 'Prel' to reduce namespace pollution.

	Addr      ==> PrelAddr     (Addr interface available in 'exts')
	ArrBase   ==> PrelArr
	CCall     ==> PrelCCall    (CCall interface available in 'exts')
	ConcBase  ==> PrelConc
	GHCerr    ==> PrelErr
	Foreign   ==> PrelForeign  (Foreign interface available in 'exts')
	GHC       ==> PrelGHC
	IOHandle  ==> PrelHandle
	IOBase    ==> PrelIOBase
	GHCmain   ==> PrelMain
	STBase    ==> PrelST
	Unsafe    ==> PrelUnsafe
	UnsafeST  ==> PrelUnsafeST

* removed ghc/Error.{lhs,hi-boot}
* moved contents of Error to GHCerr + adjusted
  import lists of files that use old Error functionality.
* moved seqError from Prelude to GHCerr.

Library changes to:

	* remove PrimIO
	* change type of _ccall_ to IO
	* incorporate Alastair Reid's new library interfaces for
	  compatibility with Hugs.

Moved intToDigit to PrelBase

OGI changes through 130397

Pragmas in interface files added

Adding and removing files