* scm/define-grob-properties.scm (all-user-grob-properties): add

* scm/define-grob-properties.scm (all-user-grob-properties): add
@code{} tags to property description.

* lily/include/line-group-group-engraver.hh (Module): remove file.

* python/convertrules.py (conv): add rule for
Engraver_group_engraver -> Engraver_group.

* lily/include/performer-group-performer.hh: analogous.

* lily/include/engraver-group-engraver.hh: rename to Engraver_group.

* lily/context-def.cc (instantiate): check for
Engraver_group_engraver and Performer_group_performer not
Engraver/Performer. Fixes crashes when doing \with { \consist .. }