[eclipse-pmc] Request to announce future removal of extension point org.

[Chris Goldthorpe <cgold@xxxxxxxxxx>]

See also: https://bugs.eclipse.org/bugs/show_bug.cgi?id=311931

This is the summary of the changes to be made, the
impact and the rationale.

The following extension point will be removed:

org.eclipse.help.base.luceneSearchParticipants

The following API classes will be removed:
org.eclipse.help.search.LuceneSearchParticipant
org.eclipse.help.search.ISearchIndex
org.eclipse.help.search.XMLSearchParticipant

Rationale for change. The class LuceneSearchParticipant exposes classes
from
Lucene in it's method parameters, specifically
org.apache.lucene.document.Document and org.apache.lucene.document.Field.
Between Lucene 1.x and 2.x there is a binary incompatibility in these Lucene
classes which is inherited by LuceneSearchParticipant, this has prevented
the
help system from upgrading to Lucene 2.x. With Lucene 3.x the situation
gets
worse because some of the methods in Document and Field which existed in
1.x
were deprecated in 2.x and removed in 3.x, clients of this extension point
could easily run into this problem.

Impact on downstream clients. Any users of this extension point will be
required to use the replacement extension point
org.eclipse.help.base.searchParticipant instead. We do not believe that
the
extension point luceneSearchParticipants is widely used.