Added note about Java 6 and Java 7 being installed at once causing problems on Windows.
Added note about Java 6 and Java 7 being installed at once causing
problems on Windows.

git-svn-id: ae08250ad33602a4155ea07c044985523749a64a@8483 67b53d14-2c14-4ace-a08f-0dab2b34000c

rzymek/vassal-src,rzymek/vassal-src