add --use-ninja option to catkin_make(_isolated) to use ninja instead of make

@tfoote @wjwwood Please review.
Is it valid for an input to be `['-GFoo']`, which would cause this to fail? It seems to be possible:

```
% cmake -GXcode ..
-- The C compiler identification is AppleClang 6.0.0.6000054
-- The CXX compiler identification is AppleClang 6.0.0.6000054
-- Check for working C compiler using: Xcode
-- Check for working C compiler using: Xcode -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler using: Xcode
^C
```

Would it not be an error if you specify both a `-G` argument in the `cmake_args` and `--use-ninja`?