[Tooling Kernel 2] Get rid of the extension point based registration and replace it with a proper plugin startup procedure.
Currently, the interplay of kernel services (low-level plugins) and
their extensions (higher-level plugins w.r.t. the architecture)
leads to an obscure and not very transparent sequence of loading plugins
and starting services. This is also not properly aligned
with the lifecycle of Eclipse 3 workbenches.
This change request is an effort to get rid of the extension mechanism
based on Eclipse extension points completely (of course,
with a deprecation phase). Note that this was done during the transition
from Eclipse 3 to E4 by Eclipse itself.
The expected effect would be (a) debuggable registration of handlers
with services, and (b) smaller service implementations
(after removal of deprecated code).
Expected changes: every kernel service gets a registerXYZ(…) method and
every extension removed from the corresponding plugin.xml
becomes a call to this method in the respective plugin activator.
Plugins are activated either explicitly by Java calls during
the workbench advisor of the RCP application plugin (strongly
recommended) or by auto-starting them in the launch configuration.
(from redmine: issue id 2590, created on 2016-05-23, closed on 2018-03-05)