[531547] Improve the filter tab descriptor extension point

Two additional parameters are now available in order to filter a tab
descriptor:

- The current workbench part
- The current selection

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=531547
Change-Id: I53a389857d75f38815030c57544b936a11ec3a05
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>
5 files changed