Shorten BlocksEditor.jar codebase.

Shorten the codebase in the jnlp file used to start the Blocks Editor.
We have removed the encrypted project information normally used for
authentication because we do not require authentication to download the
Blocks Editor (it is a public file) and having the encrypted project
information made the codebase attribute of the jnlp file sufficiently
long that it broke some implementations of Java.

Change-Id: I707f720a9f05fb0ea7097712643224eb75e27eae
Merge remote-tracking branch 'origin' into feature/simpleMusicalInstrument