call delegate '#getService()' when looking up single service

[theborakompanioni]

as classes implementing ServiceProvider may define their own custom behaviour, let the ServiceProvider instance itself fetch a single service by name instead of using an own standard strategy (using the first one returned by #getServices(Class))

this way it is prevented that a ServiceProvider must load all services of the class even if they are not generellay needed (including all side effects e.g. loading data from remote services)

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This change is 

[keilw]

Are you a JCP member? Because we cannot accept PRs from non-members in the API, RI or TCK repositories. We just had a MR1, so it may be up to the next version, if you are able to join the JCP we'd be happy to accept the PR.

[coveralls]

Coverage increased (+0.01%) to 78.212% when pulling dd4cc06 on theborakompanioni:master into 9f64034 on JavaMoney:master.

[theborakompanioni]

Hey @keilw! Thanks for your response.
Unfortunately I cannot do that, as it requires an Oracle account, which I wont create (jcp.org accounts are integrated with Oracle's Single Sign-On (SSO) login mechanism).
Would it be possible to apply the changes in an other way, e.g. by adding them yourself?
I do not mind not being the author of the changes. You can do whatever you want. I hereby grant all power to you.

Thank you for your time and service.

[keilw]

We have to see, the general mechanism is not different from other JSRs but it needs to wait till a really new JSR anyway.

[theborakompanioni]

Any updates on this @keilw ?

[keilw]

No @theborakompanioni there is no new JSR so it'll have to wait.
We have to get the 3rd Spec Lead which was recently aqcuired by Accenture, so hard to say, if they are still interested and available for that kind of stuff.