Issue #3636
Issue #3698

Closes #3689

Closes #3703

It took me forever to figure out why vim mode wasn't working, and all because the manual said to set the "keymap" option and not the "keyMap" option. I also added quotes to make it clear that "vim" is a string.

There was a typo in one of the comments (`actuall` vs `actual`).

Issue #3708

So that tiny mouse motions don't keep resetting the selected item

Closes #3698

Currently operators in most themes look like normal text because
cm-operator doesn't usually get special styling. This patch highlights
word operators (in/and/or/not) to make them stand out better.

Makes sure the selection is not entirely cleared, which causs the
on-screen keyboard to get hidden.

Disabled for Firefox, where this causes other problems.

Issue #3653

Closes gh-3687

for our purposes (=>|<=|...) works just as well as ((<=)|(=>)|...)

... taking the same approach as the C-like page.

Also
- Changes the window title from Oz mode => MscGen mode
- Makes the samples a little more uniform

Closes #3684

Issue #3666

Issue #3682

Closes #3680

And a number of other issues

Which is kind of arbitrary but seems to give less surprising
results.

Issue #3658

Closes #3667

The code is now clearer, and will prefer the nearer end of the atomic
range as long as that means there is still progress (i.e. the cursor
does not get stuck).

Issue #3658

Issue #3624

Closes #3665

So that autoclosing works.

Issue #3660

Issue #3660