Use embedded jre for sigtool

[sparkhi]

Just to mention that in our current 6.5.2 package with JRE embedded, although droid.bat correctly calls the embedded JRE to run DROID…

start "" "%DROID_HOME%/jre/bin/javaw" %DROID_OPTIONS% -jar "%DROID_HOME%droid-ui-6.5.1.jar"

…the sigtool.bat file assumes you have Java installed.

java -jar droid-tools-6.5.2.jar %*

Probably worth fixing in the next release.