Created attachment 188078 [details] [review]
assistant: remove an useless gtk_widget_reset_style() call

It's not needed to call _reset_style() here, as we did not add the
widget to the parent container yet.

Created attachment 188079 [details] [review]
assistant: pack the sidebar in a frame instead of an event box

This has mostly two advantages:
- the most obvious one is the theme can render a border around the
  sidebar if it wants to.
- we also can avoid hardcoding a container border width for the sidebar,
  and just use a padding from the theme. This also allows different
  themes to define a different padding, etc.

The drawback is we must draw the background ourselves, but it's easy
enough.

Created attachment 188080 [details]
This wasn't possible before

Review of attachment 188078 [details] [review]:

Looks like some leftover. Please commit

Review of attachment 188079 [details] [review]:

Looks great to me.

Pushed to master both patches.

Attachment 188078 [details] pushed as 6bbb9d6 - assistant: remove an useless gtk_widget_reset_style() call
Attachment 188079 [details] pushed as 8301b24 - assistant: pack the sidebar in a frame instead of an event box