This is first quick port to QtWebEngine, most of advanced features
are not working yet. Please read README.
For now, it will use separate profile directory as well as browser
session, that means you can use both QtWebEngine and QtWebKit versions
at the same time.
Fixes issue with current tab not being loaded on session restore
with "don't load tabs until selected" option.
It was needed to switch to other tab and then switch back to first tab
to actually load it.
Also pause updates of the whole browser window when restoring session.
