Compilation problems Bndtools 2.4.0

[jiri-vinarek]

After upgrade of the eclipse bndtools plugin from version 2.3.0 to 2.4.0M2 compilation errors occur. The error says "Too many Eclipse source sets defined, bnd project can have at most 2", here is the link to further discussion.

Downgrading back to 2.3.0 solves the problem but it is not sufficient as a long-term solution. I have updated the developer guide to explicitly install the older version.