Supporting template packet

Supporting template packet, you can define packet as template class or add template packet as packet field.
But visual studio has some bugs so that the template packet will lost all of its read/write member function;
Before GCC-4.5, it will leads to a compiler internal error.
Clang 3.4 has a basic bug https://bugs.llvm.org/show_bug.cgi?id=18009
So this function is only available for GCC-4.5 or above, Clang 3.5 or above, Intel compiler.

First stable version

The raw_bufffer organize a packet as a tree stored in a raw buffer.

1. Supporting POD as required type.
2. Supporting forward declared type as ANY type.
3. Supporting "reference" semantic : a child node can have one more parent nodes if the child is allocated later.