SNES: call SNESLineSearchGetSuccess before using result in PetscInfo

Microsoft's compiler warns about this use of an uninitialized variable.
SNES VISS: remove stale linesearch comment
SNESFAS: protect SNESView on smoothers before creation in SNESSetUp

When SNESView_FAS is reached before SNESSetUp or SNESSolve, the
smoothers have not been created yet, resulting in attempted
SNESView(smoothd=NULL,viewer).  Instead, just say they aren't available
yet.

Noticed-by: Patrick Farrell <patrick.farrell@imperial.ac.uk>
SNESView: notify user when SNES has not been set up yet

Suggested-by: Peter Brune <brune@mcs.anl.gov>
KSP: add man pages for pipelined CG/CR methods
KSP: add FAQ on efficient execution of piplined methods

Reference from the man pages of the pipelined KSPs, though unfortunately
I don't know how to mark-up a hyperlink.
Merge branch 'jed/fix-sneslinesearch-success-info' into maint

* jed/fix-sneslinesearch-success-info:
  SNES VISS: remove stale linesearch comment
  SNES: call SNESLineSearchGetSuccess before using result in PetscInfo
Merge branch 'jed/fix-snes-fas-view-before-setup' into maint

* jed/fix-snes-fas-view-before-setup:
  SNESView: notify user when SNES has not been set up yet
  SNESFAS: protect SNESView on smoothers before creation in SNESSetUp
Merge branch 'jed/ksp-pipe' into maint

* jed/ksp-pipe:
  KSP: add FAQ on efficient execution of piplined methods
  KSP: add man pages for pipelined CG/CR methods