process shape partly out of page; ignore replacement character `\ufff…

…d`; fix empty font name issue; #256

specify python version for publish process to avoid incompatible with…

… pytest

fixed bugs

fixed closePath issue: #146, #147

reduce converting quality criterion

fixed issues on parsing images

add resources

Merge remote-tracking branch 'origin/master'

refactor Converter #61 #64

- enhance parsing stream table, e.g. consider explicit shading when c…

…onstruct stream table

- enhance parsing lattice table, e.g. consider stream border deep into cell when parsing lattice table, detect semantic type of stroke/fill shapes in advance
- enhance text alignment detection
- fixed issue on vector graphics criterion
- switch to pytest and integrate code coverage result