Changes

[releng] Use GerritHub/Github URLs for Oomph setup

Change the Oomph setup to no longer reference git.eclipse.org.

Use raw Github URLs for the branding image and for the master location
of the Egit.setup file. Change the clone URI setup to use GerritHub
URLs.

Fix the TPD feature name; it changed from "targetplatform-feature" to
"targetplatform.feature".

Verified by performing a fresh install with fresh clones using this
modified setup.

Bug: egit-7
Change-Id: I4f609ed946eb9ef1bbabc656c5c5b97030a83caf
Signed-off-by: Thomas Wolf <twolf@apache.org>