Buildoptions are not included in ninja build

I will just put this here so it doesn't get lost in gitter chat.

buildoptions do not appear when generating ninja project. However, @stuartcarnie was able to test that they do appear on hello-world project. At the same time bgfx linux config demands -fPIC flag for all linux-* configurations and result ninja scripts do not contain them.

the same is cmake, not use buildoptions

ninja project generator state should be more complete than cmake project generator...