Previously, "Serif" would be selected in the menu when the app first
loaded, no matter what the actual setting was.

This fixes issues with Ctrl+T and the switch not reflecting correct
state when starting up -- previously, darkmode_switch was initialized in
construct_toolbar() as a local variable.

It wasn't clear what this button did without pushing it, at which point my note contents were uploaded to the Internet.

This particularly prevents the initial error all users will see when the
app first loads.

TODO: implement something more elegant.

This reverts commit 4c784b32c8.

This reverts commit c3b0a35a2e.

Opening a text file would overwrite the current draft, so for now we'll
disable this.

Requires writeas-cli v1.1

Right now this mostly just includes (most importantly) undo/redo,
and less importantly smarter deletion and keyboard navigation.

Because changing the background colour of a textview for some reason
causes text selection not to show. This is a documented issue others
experience.

This code could be refactored a little now, but it works for the
elementary and HighContrast themes.

Because for some reason this would happen seemingly at random before.
No idea why. But I did test that it occurs during save, not read.

And it doesn't appear to happen anymore.

This is manually computed, because GTK is just complaining it doesn't support percentages.

Previously, the initial dark mode toggle would cause the default
settings to be saved, before font preferences ever loaded.

Closes #11

Moves the word count to the title bar subtitle.

This checks the returned error code from `writeas` and skips the browser
opening if the status != 0.