Added patch from AsamK:

- Fixed compile of FeedReader plugin with libxml2 < 2.8
- Enabled compile of FeedReader plugin for all systems

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6061 b45a01b8-16f6-495d-af2f-9b41ad6348cc

plugins/FeedReader/util/XMLWrapper.cpp

@@ -107,7 +107,11 @@ bool XMLWrapper::convertFromString(const char *text, xmlChar *&xmlText)
 	int ret = xmlCharEncInFunc(mCharEncodingHandler, out, in);
 	if (ret >= 0) {
 		result = true;
+#if LIBXML_VERSION >= 20800
 		xmlText = xmlBufferDetach(out);
+#else
+		xmlText = xmlStrdup(xmlBufferContent(out));
+#endif
 	}
 
 	xmlBufferFree(in);