Change PutPages() visibility to protected

[eesau]

In order to use PageGroups (http://fpdf.org/en/script/script57.php) in my subclass I have to change PutPages() visibility from private to protected after every tfpdf update. I see no harm in changing the visibility of methods to protected by default.

[kazsaj]

Hello,

I don't see a reason why not. If you could create a PR, I'm sure we will get it merged.

[kazsaj]

This is now available in https://github.com/DocnetUK/tfpdf/releases/tag/v2.2.3