release: 1.3.55

release: 1.3.55

===========

* Experimental property collapse for most score-elements.  (notable
exceptions: Scripts, pedals). Change all Score_element constructors to
take a basic-property list. The suffix of a property list may be
shared by several score-elements, for instance all default G-clefs in
a score share the following settings

	   (breakable . #t)
	   (break-align-symbol . Clef_item)
	   (visibility-lambda . ,begin-of-line-visible)

This should reduce memory usage further.

* Magically fixed the disappearing Lyrics problem.

* Removed used_b_ field from Score_element.

* Massive search-replace patch: store pointers and properties
separately, in preparation of property collapse.

1.3