C++ implementation of reading HSQL's binary file format. This file
contains the actual rows for the tables, represented in an AVL tree.

Import starts from HsqlImporter, which calls to SchemaParser for some
metadata (the positions of the trees in "data" file). After that it goes
through the tree and read up the rows using HsqlRowInputStream.

Finally, it uses sdbc's XPreparedStatement to insert the rows to the
actual database.

Change-Id: If4b17572e5989c218d45880bc3fd5a8820bb4101
Reviewed-on: https://gerrit.libreoffice.org/50536Reviewed-by: Tamás Bunth <btomi96@gmail.com>
Tested-by: Tamás Bunth <btomi96@gmail.com>