API CHANGE: removal of /org.openoffice.Office/Substitution/SharePoints configuration and css.util.PathSubstitution support

[Stephan Bergmann]

This is a heads up:  In LO 5.3, the /org.openoffice.Office/Substitution 
configuration schema is removed, and the 
com.sun.star.util.PathSubstitution service no longer supports 
substitutions defined via the 
/org.openoffice.Office/Substitution/SharePoints configuration set.  See 
<https://bugs.documentfoundation.org/show_bug.cgi?id=102630> "Useless 
/org.openoffice.Office/Substitution feature" for a rationale.

Should you be using this functionality, contrary to expectations, in a 
LO extension or other third-party code, please speak up!