Fixes issue 36 from https://github.com/patricklam/JudoDB + minor bug fixes

1-     Changed HashMap to LinkedHashMap in JudoDB.java to preserve the list order.
        modified:   src/ca/patricklam/judodb/client/ClientWidget.java
        modified:   src/ca/patricklam/judodb/client/JudoDB.java

2- Fixes minor bugs in commit: fix display of courses in listbox in list view
    (31f078cd749a3996395ba242e009bf75b3329401)
        modified:   src/ca/patricklam/judodb/client/JudoDB.java
        modified:   src/ca/patricklam/judodb/client/ListWidget.java