1.	Outputable.PprStyle now carries a bit more information
	In particular, the printing style tells whether to print
	a name in unqualified form.  This used to be embedded in
	a Name, but since Names now outlive a single compilation unit,
	that's no longer appropriate.

	So now the print-unqualified predicate is passed in the printing
	style, not embedded in the Name.

   2.	I tidied up HscMain a little.  Many of the showPass messages
	have migraged into the repective pass drivers