Resolves #393 - Adds support for recording demodulated (raw) bitstream

buffers.  None of the decoders currently support this yet, but the P25
will be updated to provide bitstream output for recording.

Renames the ReusableBuffer class to ReusableFloatBuffer for
consistency.

src/main/java/io/github/dsheirer/sample/buffer/IReusableByteBufferProvider.java

@@ -0,0 +1,36 @@
+/*******************************************************************************
+ * sdr-trunk
+ * Copyright (C) 2014-2018 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by  the Free Software Foundation, either version 3 of the License, or  (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful,  but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License  along with this program.
+ * If not, see <http://www.gnu.org/licenses/>
+ *
+ ******************************************************************************/
+package io.github.dsheirer.sample.buffer;
+
+import io.github.dsheirer.sample.Listener;
+
+public interface IReusableByteBufferProvider
+{
+    /**
+     * Adds the listener to receive complex buffer samples
+     */
+    void setBufferListener(Listener<ReusableByteBuffer> listener);
+
+    /**
+     * Removes the listener from receiving complex buffer samples
+     */
+    void removeBufferListener(Listener<ReusableByteBuffer> listener);
+
+    /**
+     * Indicates if there are any complex buffer listeners registered
+     */
+    boolean hasBufferListeners();
+}