bnd driver: Set bnd property to indicate which tool is driving bnd

eclipse is added in this commit. The build and gradle template are also
updated.

Save actions also added some @Override annotations.

Signed-off-by: BJ Hargrave <bj@bjhargrave.com>
Merge pull request #875 from bjhargrave/bnd-driver

bnd driver: Set bnd property to indicate which tool is driving bnd
gradle: driver is now set by BndPlugin

Signed-off-by: BJ Hargrave <bj@bjhargrave.com>
Use new Workspace.setDriver method to set bnd driver

This is instead of directly setting the -bnd-driver workspace property.

Signed-off-by: BJ Hargrave <bj@bjhargrave.com>
Merge pull request #876 from bjhargrave/setdriver

Use new driver API in Workspace to set the driver to "eclipse"
gradle: Remove unneeded import from init.gradle script

Signed-off-by: BJ Hargrave <bj@bjhargrave.com>
Merge pull request #877 from bjhargrave/remove-import

gradle: Remove unneeded import from init.gradle script
gradle: Use fixed file name for downloaded bnd jar

The URI provided by the bnd_jar property may not have a valid file name
as the last component of the URI's path. This is true for JPM URLs.

Signed-off-by: BJ Hargrave <bj@bjhargrave.com>
Merge pull request #879 from bjhargrave/bndjarfile

gradle: Use fixed file name for downloaded bnd jar