Added error correction to the metadata of LDU1 and LDU2.

Refactored implementation of p25p1_ldu1.c and p25p1_ldu2.c. There are less duplicities now and hopefully is easier to read and maintain.
Added a unit test for the Hamming algorithm.

test/golay24-test.cpp

@@ -1,5 +1,10 @@
+/**
+ * Unit tests for the Golay24 implementation.
+ */
+
 #include "gtest/gtest.h"
 #include "gmock/gmock.h"
+
 #include "Golay24.hpp"
 
 class Golay24Test : public testing::Test