Trying to Cythonize PDFMiner's bottlenecks.
Current solution: https://github.com/hellpanderrr/cythonized_pdfminer/blob/master/pdfminer/plane.pyx
Current solution: https://github.com/hellpanderrr/cythonized_pdfminer/blob/master/pdfminer/layout_c.pyx
200-300% on text-heavy pdfs