Version "3" of binary OCAF persistence (BinOcaf)

New version of the OCAF binary persistance format is created.

This improvement unifies the inclusion of non-OCAF data into persistent
documents. In format version 2 there was only one such data block - Shapes
section. In the new format version 3 it is possible to create any number of
custom sections, the Shapes being just one of them.

Each Section is unquely identified by ASCII name string and has also the
attribute IsPostRead. This attribute defines if the Section is read before or
after the OCAF data. In the former case the BinOcaf attribute drivers can have
access to non-OCAF data that are read in advance (as with the SHAPES section).

To use custom sections in OCAF binary documents, it will be necessary to
subclass DocumentRetrievalDriver and DocumentStorageDriver from BinLDrivers,
with the relevant definition of virtual methods that process the section data.

Compatibility with documents written in format version 2 is preserved in
DocumentRetrievalDriver.