message: streams: Remove special cases for ancient MSVC
  Quite sure that we haven't supported MSVC 6.0 for ages (MSC_VER 1300 is
  >= MSVC++ 7.0) but with the C++11 switch we can be sure.
diff: @@ -107,12 +107,10 @@ public:
  Init(nTypeIn, nVersionIn);
  }
  -#if !defined(_MSC_VER) || _MSC_VER >= 1300
  CDataStream(const char* pbegin, const char* pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend)
  {
  Init(nTypeIn, nVersionIn);
  }
  -#endif
  CDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end())
  {
  @@ -195,7 +193,6 @@ public:
  vch.insert(it, first, last);
  }
  -#if !defined(_MSC_VER) || _MSC_VER >= 1300
  void insert(iterator it, const char* first, const char* last)
  {
  if (last == first) return;
  @@ -209,7 +206,6 @@ public:
  else
  vch.insert(it, first, last);
  }
  -#endif
  iterator erase(iterator it)
  {
  