- made it easier to reuse sources.cfg

sources.cfg

 [buildout]
 extends = http://svn.zope.org/repos/main/zopetoolkit/trunk/ztk-sources.cfg
+svn-zope-org = ^
 
 [sources]
 # Zope2-specific
-AccessControl = svn ^/AccessControl/trunk
-Acquisition = svn ^/Acquisition/trunk
-DateTime = svn ^/DateTime/trunk
-DocumentTemplate = svn ^/DocumentTemplate/trunk
-ExtensionClass = svn ^/ExtensionClass/trunk
-initgroups = svn ^/initgroups/trunk
-Missing = svn ^/Missing/trunk
-MultiMapping = svn ^/MultiMapping/trunk
-nt_svcutils = svn ^/nt_svcutils/trunk
-Persistence = svn ^/Persistence/trunk
-Products.OFSP = svn ^/Products.OFSP/trunk
-Products.ZCatalog = svn ^/Products.ZCatalog/trunk
-Products.ZCTextIndex = svn ^/Products.ZCTextIndex/trunk
-Record = svn ^/Record/trunk
-tempstorage = svn ^/tempstorage/trunk
-zExceptions = svn ^/zExceptions/trunk
-zLOG = svn ^/zLOG/trunk
-ZopeUndo = svn ^/ZopeUndo/trunk
+AccessControl = svn ${buildout:svn-zope-org}/AccessControl/trunk
+Acquisition = svn ${buildout:svn-zope-org}/Acquisition/trunk
+DateTime = svn ${buildout:svn-zope-org}/DateTime/trunk
+DocumentTemplate = svn ${buildout:svn-zope-org}/DocumentTemplate/trunk
+ExtensionClass = svn ${buildout:svn-zope-org}/ExtensionClass/trunk
+initgroups = svn ${buildout:svn-zope-org}/initgroups/trunk
+Missing = svn ${buildout:svn-zope-org}/Missing/trunk
+MultiMapping = svn ${buildout:svn-zope-org}/MultiMapping/trunk
+nt_svcutils = svn ${buildout:svn-zope-org}/nt_svcutils/trunk
+Persistence = svn ${buildout:svn-zope-org}/Persistence/trunk
+Products.OFSP = svn ${buildout:svn-zope-org}/Products.OFSP/trunk
+Products.ZCatalog = svn ${buildout:svn-zope-org}/Products.ZCatalog/trunk
+Products.ZCTextIndex = svn ${buildout:svn-zope-org}/Products.ZCTextIndex/trunk
+Record = svn ${buildout:svn-zope-org}/Record/trunk
+tempstorage = svn ${buildout:svn-zope-org}/tempstorage/trunk
+zExceptions = svn ${buildout:svn-zope-org}/zExceptions/trunk
+zLOG = svn ${buildout:svn-zope-org}/zLOG/trunk
+ZopeUndo = svn ${buildout:svn-zope-org}/ZopeUndo/trunk
 
 # Deprecated / CMF dependencies
-Products.BTreeFolder2 = svn ^/Products.BTreeFolder2/trunk
-Products.ExternalMethod = svn ^/Products.ExternalMethod/trunk
-Products.MailHost = svn ^/Products.MailHost/trunk
-Products.PythonScripts = svn ^/Products.PythonScripts/trunk
-Products.StandardCacheManagers = svn ^/Products.StandardCacheManagers/trunk
+Products.BTreeFolder2 = svn ${buildout:svn-zope-org}/Products.BTreeFolder2/trunk
+Products.ExternalMethod = svn ${buildout:svn-zope-org}/Products.ExternalMethod/trunk
+Products.MailHost = svn ${buildout:svn-zope-org}/Products.MailHost/trunk
+Products.PythonScripts = svn ${buildout:svn-zope-org}/Products.PythonScripts/trunk
+Products.StandardCacheManagers = svn ${buildout:svn-zope-org}/Products.StandardCacheManagers/trunk