#310 Add XIncludes to Assembly Schema

[Thomas Schraitle]

Problem

Currently, with DocBook 5.1 CR3 the schema has an assembly.rn{c,g} companion. However, this file/schema does not have any XIncludes elements at all.

Proposed Solution

For writers who want to split up their assembly file into different parts and xinclude it, it would be convenient to add the XInclude elements into the Assembly schema. The user could then select between an assembly.rn{c,g} or assemblyxi.rn{c,g} schema.