- fix a typo s/Commponent/Component/.
- Add &std_pdb_compat() to the new PDB procedures (I realize that's probably
  what the contributor was asking about, back in !446). Not sure if it's right
  as there were none in this file, but these are clearly just wrappers around
  GEGL ops, so it seems fitting.
- Some alignment fixes.
- More accurate "$since" variables.

(cherry picked from commit 66ef1ef1)