HCOLL-136 HCOLL-137 HCOLL-153 HCOLL-160

1. Separated ChronicleMapBuilder (for non-Byteable values) and
OffHeapUpdatableChronicleMapBuilder (for Byteable values) with common base
AbstractChronicleMapBuilder (public just to inherit common javadocs)

2. Added ChronicleHashBuilder.keyDeserializationFactory() and
AbstractChronicleMapBuilder.valueDeserializationFactory() (former
ChronicleMapBuilder.valueFactory() method)

3. Changed ChronicleMap.get(), getUsing() API and impl to what was
initially intended - now they ALWAYS returns null, if key is absent

4. acquireUsing() API, common for the cases with Byteable and non-Byteable
values: puts defaultValue or defaultValueProvider.get(key), if the key is
absent, then acquireUsing() behaves just like getUsing()

5. For off0heap updatable ChronicleMaps (Byteable values), added
prepareValueBytes() configuration which formalizes zeroing out value bytes

6. Javadoc fixes and improvements

src/main/java/net/openhft/chronicle/map/PrepareValueBytes.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2014 Higher Frequency Trading http://www.higherfrequencytrading.com
+ *
+ * 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 net.openhft.chronicle.map;
+
+import net.openhft.lang.io.Bytes;
+
+import java.io.Serializable;
+
+public interface PrepareValueBytes<K> extends Serializable {
+
+    void prepare(Bytes bytes, K key);
+}