vector subscript out of range assertion hit on windows

[Dennis Knochenwefel]

in src/zorbatypes/binary.cpp a lot of vectors are accessed with [0], e.g.:

    aBase64.theData.resize(
      copy_without_ws( aString, aLength, &aBase64.theData[0] )
    );

if in this case aLength is of size 0 the assertion "vector subscript out of range" is hit on windows in debug build. This happens because size == pos in std::vector implementation on windows:

  reference operator[](size_type _Pos)
  { // subscript mutable sequence
   #if _ITERATOR_DEBUG_LEVEL == 2
  if (size() <= _Pos)
   { // report error
   _DEBUG_ERROR("vector subscript out of range");
   _SCL_SECURE_OUT_OF_RANGE;
   }

Therefore, before accessing a vector with [0] one must check whether the size of the vector is > 0. Otherwise the mentioned assertion will trigger.