message: Transform text position in `Frame::fill_text`
  Also add a warning explaining its current limitations.
diff: @@ -159,18 +159,38 @@ impl Frame {
  /// Draws the characters of the given [`Text`] on the [`Frame`], filling
  /// them with the given color.
  ///
  + /// __Warning:__ Text currently does not work well with rotations and scale
  + /// transforms! The position will be correctly transformed, but the
  + /// resulting glyphs will not be rotated or scaled properly.
  + ///
  + /// Additionally, all text will be rendered on top of all the layers of
  + /// a [`Canvas`]. Therefore, it is currently only meant to be used for
  + /// overlays, which is the most common use case.
  + ///
  + /// Support for vectorial text is planned, and should address all these
  + /// limitations.
  + ///
  /// [`Text`]: struct.Text.html
  /// [`Frame`]: struct.Frame.html
  - #[inline]
  pub fn fill_text(&mut self, text: Text) {
  use std::f32;
  + let position = if self.transforms.current.is_identity {
  + text.position
  + } else {
  + let transformed = self.transforms.current.raw.transform_point(
  + lyon::math::Point::new(text.position.x, text.position.y),
  + );
  +
  + Point::new(transformed.x, transformed.y)
  + };
  +
  // TODO: Use vectorial text instead of primitive
  self.primitives.push(Primitive::Text {
  content: text.content,
  bounds: Rectangle {
  - x: text.position.x,
  - y: text.position.y,
  + x: position.x,
  + y: position.y,
  width: f32::INFINITY,
  height: f32::INFINITY,
  },
  