Rename `_ALIGNBYTES_` to `CUBISM_ALIGNMENT`.

Not sure about this, but now Cubism automatically defines
`CUBISM_ALIGNMENT` if it is not already defined.
That means that if the app intends to define the value,
it must define it before including _any_ Cubism header.

An alternative would be to put these ifdefs to Matrix3D.h (the only file
using the constant), but probably better to be strict.

include/Cubism/Common.h

@@ -11,6 +11,14 @@
 #define CUBISM_ON_FERMI
 #endif
 
+#ifdef _ALIGNBYTES_
+#warning _ALIGNBYTES_ is deprecated, use CUBISM_ALIGN_BYTES instead.
+#define CUBISM_ALIGNMENT _ALIGNBYTES_
+#elif !defined(CUBISM_ALIGNMENT)
+#define CUBISM_ALIGNMENT  // If you get duplicate definition, put all Cubism
+                          // includes after the main header include.
+#endif
+
 #ifndef CUBISM_NAMESPACE_BEGIN
 #define CUBISM_NAMESPACE_BEGIN namespace cubism {
 #endif

include/Cubism/Matrix3D.h

@@ -59,8 +59,8 @@ public:
 
         //allocator<DataType> alloc;
         //m_pData = alloc.allocate(m_nElements);
-        const int retval = posix_memalign((void **)&m_pData, std::max(8, _ALIGNBYTES_), sizeof(DataType)*m_nElements);
-        (void)retval;  // Silent -Wunused-variable.
+        const int retval = posix_memalign((void **)&m_pData, std::max(8, CUBISM_ALIGNMENT), sizeof(DataType)*m_nElements);
+        (void)(retval + retval);  // Silent -Wunused-variable.
 //      printf("Allocated %d bytes at 0x%lx\n", sizeof(DataType)*m_nElements, m_pData); // peh
         assert(retval == 0);
         assert(m_pData != NULL);