• stop sharing a reference to cached PPI docs, which led to spooky
  action at a distance
  
• PkgVersion no longer surrounds the new $VERSION assignment with a
  bare block
  
• if there's a blank line after the package statement (and any number
  of comment-only lines), PkgVersion will use that for a $VERSION
  assignment, rather than insert a new line; this can be made mandatory
  with die_on_line_insertion