Moved version directives to the bottom of the loaddata section.
Used the :ticket: syntax more extensively
Used https for most *.python.org links
Updated some other external links in the docs
Made model_regress unpickling test CWD-independent

Refs #24007. Thanks Tim Graham for his help with the patch.
Fixed refs #24007 test on Windows.
Added words to docs wordlist.
Added upgrade instructions for deprecated model _meta permission methods.