CLion exporter adds -std=c++11 also on .c files

[t0m]

Because we envision a future CMake exporter being much more general. See the discussion here:

CMake support in the Projucer

Hi all, The JUCE team is currently investigating the best way of incorporating CMake support into the Projucer and it would be useful to get some community feedback. Please let us know, in as much detail as possible, how you would like to use CMake with JUCE. At the moment I think the best workflow we’ve devised is to include a CMake exporter in the Projucer that is different to all the other exporters. This new type of exporter will contain a single input field that allows you to write arbitr…

Does the invalid flag cause a warning or an error?