Moving to M3
moving to 2.5 as part of the CDT upstream strategy.
moved to scott as he is doing this work.
As described in the comments on this bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=522376 It seems that the CDT project lead is not going to mature the core build API sufficiently until at least CDT photon (June 2018). So I'm moving this to 2.6
We long longer support eclipse.