macports without XCode

[Jeremy Lavergne]

> Which packages if I can ask?  because they might be packages that I do not want nor need.

I grepped to find 148 packages using our xcode includes explicitly (xcode.*1\.0). There may be more that were manually built without using our PortGroup files.

> How so?  I would have imagined it's the CLT that make the difference, after all they mast be installed for macports.

...and Xcode must also be installed.

We do version detection using `xcodebuild -version` (see zlib for an example). We would need an alternative to this if it's not installed.