build: setting pretty="false" generates an uncompressed index

This is a bug in the repoindex bundles that is used to generate the
indexes. So remove the pretty setting to make sure we do generate
compressed indexes.

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
build: change the replace token to @qualifier@

To prepare for the gradle build

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
build: no need to explicitly copy in the apache ace bnd repository jar

It's already included in the build.jar through the bnd file.

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
build: be more explicit about included/excluded jars

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
build: move internal p2 ant targets into their own file

To prepare for the gradle build.

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
gradle: minor tweak to the dot file

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
gradle: add p2 generation

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