CP-5524: Made Java SDK backwards compatible.

Autogenerate overloads for java methods the signature of which has changed.
Added documentation to fields, classes, methods and parameters with regards to
the first release they became available.

Signed-off-by: Konstantina Chremmou <konstantina.chremmou@citrix.com>
Made method Connection.dispatch protected according to Cloudstack request.

Signed-off-by: Konstantina Chremmou <konstantina.chremmou@citrix.com>