Added support for new strict/relaxed version of PdfFileReader; defaults to strict.
Added support for new strict/relaxed version of PdfFileReader; defaults to strict.

manuelzs/PyPDF2,dellelce/ypypdf2,manuelzs/PyPDF2,vfulco/PyPDF2,KumaranKamalanathan/PyPDF2,magnet-cl/PyPDF2,dellelce/ypypdf2,magnet-cl/PyPDF2,melsior/PyPDF2,melsior/PyPDF2,vfulco/PyPDF2,KumaranKamalanathan/PyPDF2