Provide translation for internal function from bannertopdf filter

[appr0ve]

Hallo.

In process for solving following issue #99 found that generate_banner_pdf function have untranslatable strings used for creating test print page:
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L689
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L695
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L701
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L706
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L709
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L714
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L717
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L723
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L729
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L734
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L739
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L784
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L790
https://github.com/OpenPrinting/libcupsfilters/blob/2.1.1/cupsfilters/bannertopdf.c#L795

libcupsfilters already include gettext dependency.

We can use translation domain presented in current repository for that?

[michaelrsweet]

This needs to be over in the libcupsfilters repo...

[appr0ve]

We can use translation domain presented in current repository for that?

What about that? Locales present in cups repository.