Add discussion regarding available services (e.g. builds, Sonar) including SLA

Submitted by Wayne Beaton @wbeaton

Link to original bug (#518974)

Description

Let's consider adding some discussion (or update the existing discussion) regarding services and be sure to make explicit the service levels.

https://wiki.eclipse.org/IT_SLA

Let's be careful, here, about duplicating any information. If the right home for this information is in the wiki (maintained by the webmaster), then the handbook should provide a pointer with some text that at least indicates that there are different tiers of service.

While we're at it, we should likely include an indication of SLA in wiki entries.

e.g. the Developer Resources page includes a link to Sonar support; both that page and the Sonar page itself should explicitly state the service tier and what that means.