introduce CustomService

CustomService is an AsyncMultiService that can be custom to one process.

Custom services are attached to the master, started, and reconfigured asynchronously

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
CustomService config tests

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
attempt for an integration test

Need more unittests for the CustomServiceFactory..

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
basic unit test for CustomServiceFactory
finish the integration test

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
refactor the integration test for reusability

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
documentation for custom services

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
fix PR reviews

- doc fixing
- definitly move ReconfigurableServiceMixin to buildbot.util.service

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
simplify links

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
add a release note

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
attempt for a single class implementation

untested

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
make the integration test work

new services, and deleted services works as expected on reconfig

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
address review comments

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
remaining doc update and unit tests

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Merge pull request #1378 from tardyp/services

Services