Sketching out component configuration model & API.
Added initial cut of implementation.
Finished implementation; ready for merge.

Change-Id: I385181c0591604a5c44986b97fb881eba7e0528e
diff --git a/core/net/src/main/java/org/onosproject/cfg/impl/ConfigPropertyDefinitions.java b/core/net/src/main/java/org/onosproject/cfg/impl/ConfigPropertyDefinitions.java
new file mode 100644
index 0000000..0f416c7
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/cfg/impl/ConfigPropertyDefinitions.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cfg.impl;
+
+import com.google.common.collect.ImmutableSet;
+import org.onosproject.cfg.ConfigProperty;
+import org.onosproject.cfg.ConfigProperty.Type;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.util.Set;
+
+import static org.onosproject.cfg.ConfigProperty.defineProperty;
+
+/**
+ * Utility for writing and reading configuration property definition file.
+ */
+public final class ConfigPropertyDefinitions {
+
+    private static final String FMT = "%s|%s|%s|%s\n";
+    private static final String SEP = "\\|";
+    private static final String COMMENT = "#";
+
+    private ConfigPropertyDefinitions() {
+    }
+
+    /**
+     * Writes the specified set of property definitions into the given output
+     * stream.
+     *
+     * @param stream output stream
+     * @param props  properties whose definitions are to be written
+     * @throws java.io.IOException if unable to write the stream
+     */
+    public static void write(OutputStream stream, Set<ConfigProperty> props) throws IOException {
+        try (PrintWriter pw = new PrintWriter(new OutputStreamWriter(stream))) {
+            props.forEach(p -> pw.format(FMT, p.name(), p.type(), p.description(), p.defaultValue()));
+        }
+    }
+
+    /**
+     * Reads the specified input stream and creates from its contents a
+     * set of property definitions.
+     *
+     * @param stream input stream
+     * @return properties whose definitions are contained in the stream
+     * @throws java.io.IOException if unable to read the stream
+     */
+    public static Set<ConfigProperty> read(InputStream stream) throws IOException {
+        ImmutableSet.Builder<ConfigProperty> builder = ImmutableSet.builder();
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(stream))) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                if (!line.isEmpty() && !line.startsWith(COMMENT)) {
+                    String[] f = line.split(SEP, 4);
+                    builder.add(defineProperty(f[0], Type.valueOf(f[1]), f[2], f[3]));
+                }
+            }
+        }
+        return builder.build();
+    }
+
+}