Feature: pdf export settings

[vidaktobyl]

We would love to have a simple parameter in the configuration menu to adjust the PDF-generation, e.g. support for standard ghostscript parameters, such as page size, page numbers, orientation, etc.

no fancy WYSIWYG editor, just a text-field to add individual parameters.

[kisero]

when we get to the reporting side of things on the product roamdap we will conisder this type of funtionality, generating pdfs is pretty complex and time consuming.