It's no longer allowed on IE10, and not needed on IE9.

Closes #911

Issue #907

(It used to only notice when a single span filled the whole line.)

It's already cached globally, but such cache lookups are not that cheap.

Cut down on round-trips (and improve caching) by measuing all
characters in a line at once, and caching the resulting object, rather
than forcing an (expensive) DOM layout for every char that is
measured, and caching per-char.

That were used to find the precise width at which something wraps.

To allow arbitrary folding of text, and replacement with widgets.

Remove old line folding system.

To prevent repeated re-sorting and general silly side effects.

.. to be a little less gigantic and convoluted.

Prevents weird side effects after setting the selection on an
unfocused editor.

The class is now specified as an option, rather than a separate argument
(and is thus optional).

Incompatible API change.

Experimental feature. Makes a span impossible to edit.

Otherwise, at some zoom levels, rounding errors would cause a
feedback loop that made the scroll position 'drift'.

Closes #907

This is an experimental feature. Not stable, nor well tested.

Atomic markers allow a marked range to act as an indivisible unit,
as far as cursor movement, selection, and deletion is concerned.

Paves the way for widget placeholders that behave properly, and
chunks of non-editable text in an editable document.

Closes #878

Allow slashes and question marks in unquoted attribute values
(not sure why those were disallowed in the first place) and
properly style the token after a value-less attribute.

Closes #904
Closes #902