createBase64Binary() API too subtle

[Paul J. Lucas]

ItemFactory contains:

  Item createBase64Binary(const char* aBinData, size_t aLength) = 0;
  Item createBase64Binary(const unsigned char* aBinData, size_t aLength) = 0;

The former expects base64-encoded data; the latter expected raw binary data that is then encoded. IMHO, the distinction between char* and unsigned char* is too subtle. You can't tell by looking at a call to either function whether it's calling the first or second -- you have to look up the type of the first argument.

IMHO, it would be better to merge the two functions (that take a const char*) and add a 3rd argument:

    bool isEncoded

that explicitly specifies whether the data is encoded or not. This API change should be done for Zorba 3.0. Initially assigned to Matthias for later reassignment.