LP:712720 - handlersocket does not compile against MariaDB 5.3

Even after working around bug 712714 , handlersocket does not compile against maria-5.3

To repeat, configure handlersocket

./configure --with-mysql-source=/home/philips/bzr/mysql-5.3.0-MariaDB-alpha --with-mysql-bindir=/home/philips/bzr/maria-5.3-bintar/bin/

then run "make" and you will get

/home/philips/bzr/mysql-5.3.0-MariaDB-alpha/sql/handler.h: In member function ‘void dena::dbcontext::cmd_find_internal(dena::dbcallback_i&, const dena::prep_stmt&, ha_rkey_function, const dena::cmd_exec_args&)’:
/home/philips/bzr/mysql-5.3.0-MariaDB-alpha/sql/handler.h:1805: error: ‘virtual int handler::index_read_map(uchar*, const uchar*, key_part_map, ha_rkey_function)’ is protected
database.cpp:793: error: within this context
/home/philips/bzr/mysql-5.3.0-MariaDB-alpha/sql/handler.h:1823: error: ‘virtual int handler::index_prev(uchar*)’ is protected
database.cpp:798: error: within this context
/home/philips/bzr/mysql-5.3.0-MariaDB-alpha/sql/handler.h:1821: error: ‘virtual int handler::index_next(uchar*)’ is protected
database.cpp:802: error: within this context
/home/philips/bzr/mysql-5.3.0-MariaDB-alpha/sql/handler.h:1829: error: ‘virtual int handler::index_next_same(uchar*, const uchar*, uint)’ is protected
database.cpp:805: error: within this context
make[2]: *** [handlersocket_la-database.lo] Error 1