the old code was allowing the main thread to read .port before it had
been updated, and was binding to sockets that were already in use on
Windows. instead, we use a system-assigned free port and block the main
thread until it's been allocated
- use a non-daemonized python thread
- shut the server down on exit, including from profile manager
- use a timeout on requests, or the connection that webengine holds open
will block the thread and prevent it from exiting when anki closes
- js code that was previously bundled in .py files is now in the
web folder
- add helpers to create links to bundled files, and update
stdHtml() to accept a list of javascript files to include
instead of text
- render MathJax in card layout and preview screens - these should be
updated in the future to update the document dynamically like the
reviewer does
- start media server earlier so it can be used to serve content for
the toolbar, etc
- work around a bug in WebEngine on Windows that could cause the
media server to hang
