Of course you need the misterbundles development package...
Here is what you will find in the README.txt :

####################
##     DEVELOPERS     ##
####################

When you modify the code, you can compile all the mister bundles project files by entering the command :
>make
in the misterbundles/src directory : it will create the jar files in the build directory and
copy them automatically to /usr/java/jes2.0/bundles

To compile only specific files after modification e.g. mbportal.jar do :
>make
in the mbportal directory !!

In jes, update the bundle :
>up mbportal
and see the modifications at https://localhost:9090