[Suggest] New branch for Milestones 2.0.0

[dota17]

@baylesj
Hi, to avoid breaking the compilation of master branch when we creat new PRs for milestones 2.0.0, is it better to create new branch for them?

Recent releated issue : #990

[baylesj]

Hmmmm. I would generally advocate for people to check out tags instead of rolling against head. I definitely think we should not have C++14 features in 1.9.x branches, and consider that a breaking change for 2.0.

I'll resolve this when I have pulled out the deprecated flags.