Changes

Bug 581504: Remove ip_log.xml use/requirement

With the new tooling from EF (e.g. dash license tool) we
no longer need to maintain ip_log.xml in Orbit.

We aren't deleting all exiting ip_log.xml files as
that would cause all existing bundles to have their
qualifiers touched which is undesirable. (We could
exclude ip_log.xml from jgit timestamp, but that leads
to some special cases that aren't worth the effort.)

The EBR plug-ins provide the ip_log.xml verification,
therefore, besides documentation updates, this simply
bumps to the newest EBR version that requires EBR
PR https://github.com/eclipse/ebr/pull/61 to be
merged and built.

Change-Id: Ia0f814edea57984f71aac342f4fd973d8bf5fe56