Integrate flycheck-xcode

[jojojames]

Creating issue to track adding this to xcode-mode.

[jojojames]

Submitted to Melpa, after that I'll add a package-require to xcode-mode and other glue code if necesary.

[jojojames]

This also looks good by the way for metadata handling.

https://github.com/nhojb/xcode-project

[nicklanasa]

That will indeed help will building and running the project. I’ll add that as a dependency if it works well enough

[jojojames]

It's on melpa now, I'll get to adding this soon.

Going a check against a workspace might be tricky though since there are many (no default?).