gradle: temporary build adjustments

- gradle: a script to fully exercise the gradle build
- gradle: we need an up-to-date bnd for the gradle build
- gradle: we don't want verbose mode for now
- cnf   : files to make it an example project

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
bndoc: disable bundle/release/export/bundleTest for the gradle build

Like was done for the Ant build

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
bndlib.tests: fix the test directory setup

So that it can be built by the template

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>