Tags: Added <emit#csv/>.

Added RXML-support for emitting values from csv-files.

Fixes [bug 7147]
Merge branch 'patches/bug7147' into 5.1

* patches/bug7147:
  Tags: Added <emit#csv/>.
Tags: Survive without Parser.CSV.

Pike 7.8 doesn't have Parser.CSV, so provide a fallback implementation.
Tags: More stuff to survive without Parser.CSV.

Parser.Tabular in Pike 7.8 lacks some stuff that Parser.CSV needs,
so incorporate it in the fallback code.
Merge branch 'patches/bug7147' into 5.1

* patches/bug7147:
  Tags: More stuff to survive without Parser.CSV.
  Tags: Survive without Parser.CSV.