Add a Java implementation of packed formats.

Also add a test case and update the layout of the Java build.

lang/java/src/com/wiredtiger/db/PackUtil.java

@@ -0,0 +1,37 @@
+package com.wiredtiger.db;
+
+import java.lang.String;
+
+/*
+ * Package-private - not part of the public API.
+ */
+class PackUtil {
+    /* Contants. */
+    final static byte NEG_MULTI_MARKER = (byte)0x10;
+    final static byte NEG_2BYTE_MARKER = (byte)0x20;
+    final static byte NEG_1BYTE_MARKER = (byte)0x40;
+    final static byte POS_1BYTE_MARKER = (byte)0x80;
+    final static byte POS_2BYTE_MARKER = (byte)0xc0;
+    final static byte POS_MULTI_MARKER = (byte)0xe0;
+
+    final static int NEG_1BYTE_MIN = ((-1) << 6);
+    final static int NEG_2BYTE_MIN = (((-1) << 13) + NEG_1BYTE_MIN);
+    final static int POS_1BYTE_MAX = ((1 << 6) - 1);
+    final static int POS_2BYTE_MAX = ((1 << 13) + POS_1BYTE_MAX);
+
+    // See: http://docs.python.org/2/library/struct.html for an explanation
+    // of what these special characters mean.
+    // TODO: Care about byte ordering and padding in packed formats.
+    final static String PackSpecialCharacters = "@=<>!x";
+
+    final static int SIZEOF_LONG = 8;
+
+    /*
+     * Extract bits <start> to <end> from a value (counting from LSB == 0).
+     */
+    public static byte GET_BITS(long x, int start, int end) {
+        return (byte)((x & ((1 << start) - 1)) >> end);
+    }
+    
+
+}