upload v1.19.3

Merge branch 'master' of https://github.com/rk700/PyMuPDF

Update symbols.txt

Update README.md

hotfixing pymupdf#1266

Merge branch 'master' of https://github.com/rk700/PyMuPDF

improve test scripts

`show_pdf_page` and `insert_image` are now tested with rotated insertions.

upload v1.18.16

update documentation to v1.18.15

Upgrade to version 1.18.14.