This is bad, I'll explain why:
When Introjucer/Projucer saves files, it converts them to CRLF ("\r\n", Windows "normal" line endings).
When Xcode saves files, it converts them to LF ("\n", "normal" line endings).
Giving the Projucer a shot, I change the GUI layout, am happy, and get a diff which is huge. Huge diffs make merges/stashes etc impossible and kill the benefits of git. So I have to run "dos2unix" on the file for a reasonable diff. I don't use the Projucer as my only IDE because Xcode has a lot of nicer stuff (completions, navigation, compiler errors) or maybe I'm just used to it.
What "modern" editors, like Atom, do, is preserve the line endings of the file. Let's call it "liberal". Would had been nice if Xcode and Projucer were liberal. However I can't expect Xcode to change because Apple tend to try to force us to do the "right thing" and use the "right" line endings. But maybe at least Introjucer/Projucer can be liberal.