Community is meant to be fully featured with the only catch being that the license is limited to individuals and very smallcompaniesteams.
At least that's the way I understand it.
FTFY.
Community is licensed to be used for teams of up to 5 developers, in a non-enterprise environment. We considered using VS Community and the free cloud equivalent of Team Foundation Server a few years ago since our team consists of 4-5 developers, however being an Enterprise we are disqualified.
As far as CMake support, my understanding is that it should be included, but Google searches and perusing the 'What's New in 2017' page, along with the product comparison, has produced no documentation as such. Interested to hear if it's there, and if it is, what you think of the integration.