Results 2 issues of DS

With [this PDF-file](https://github.com/0xabu/pdfannots/files/4470936/test.pdf) the words are not split. It's an OCR-scan. I tried modifying the word_margin in LAParams to no avail. When exporting the highlights using PDF Expert (my macOS-PDF...

bug
pdfminer

I added two minutes leeway to account for clock skew. https://tools.ietf.org/html/rfc7519#section-4.1.5