add style to version changed in html docs

- italic text, like the default
- indent the block
wrap text in pre tags

so that they don't stretch beyond their container
msg spec 5.0
make InteractiveShell.banner a property
unify visual line handling
Trim which options are exposed on kernelspec CLI
Don't auto-move .config/ipython if symbolic link
remove an inappropriate `!`

the logic was backwards.
fix engine startup files

engine startup_file and startup_command are ignored in 2.0
Merge pull request #5716 from jakobgager/latex_booktabs

Add booktabs package to latex base.tplx
Merge pull request #5806 from bfredl/fixlink

Don't auto-move .config/ipython if symbolic link
Drop log level to info for Qt console shutdown
Merge pull request #5805 from minrk/engine_startup

fix engine startup files
Merge pull request #5804 from minrk/invert-callback-clear

remove an inappropriate `!`
apply json_clean to comm_msg content

The same code that is applied to other user-generated json content.

avoids errors in json encoding.
disallow nan in JSON serialization

since it's not actually valid JSON
Linkify some API docs
Remove -i options from mv, rm and cp aliases

This was arguably useful in the terminal, but it means these aliases
can't be used from any of the ZMQ frontends. And users familiar with the
shell shouldn't find the default (non -i) behaviour surprising.

Closes gh-5729, which accidentally included an unrelated change.
Merge pull request #5810 from minrk/clean-comm-msg

apply json_clean to comm_msg content
Add output to IPython directive when in verbatim mode.
Addresses #5776.