JDSC 0.5.9a released

JDSC 0.5.9a patches the following issues:

- When connecting to the official JDuplicate Server (which is
currently running 0.5.10 beta), blank letters would not be
playable

- DUPLICATETOURNEY mode which computes the TOP as played in Duplicate tournaments, is now supported

Use this file only when connecting to a 0.5.10 server, like the one online at jdupserver.thelemmings.net. Stay tuned for the 0.5.10 release :)