Expose public header files correctly

[dral3x]

While using the library via cocoapods with use_frameworks!, the app cannot compile properly because the file PTURLRequestOperation.h is not exposed as header (it was recently moved from Library/Private Headears to Library.

With this change, all public header files are correctly exposed (while leaving private headers... private) and so the app can compile properly.

[hamchapman]

The header is already public, is it not?

Not sure why we'd now need to specify the public_header_files in the podspec.

Can you explain why? I may well just be ignorant!

[dral3x]

I don't have a clear explanation for that, sorry. Probably I know less things than you!

I simply notice that if you don't expose your headers (privately or publicly), the library cannot be built as framework. Maybe it's a bug or a specification of cocoapods regarding the usage of private_header_files.

[dral3x]

To be fair, i'm using the latest version of cocoapods (1.1.0.beta.1). Maybe is something related to that.
Explicitly expose public headers can't hurt anyways.

[hamchapman]

Yeah, sounds reasonable to specify them as public in the podspec.

I'll do some reading just to sanity check it, then merge it (assuming it all checks out 👍 )