* [egui_web] Always use an even canvas size
Fixes https://github.com/emilk/egui/issues/103
* [egui_web] Position canvas at top of screen
This avoids jumpyness when resizing,
caused by rounding height to an even number
Add support for primary, secondary and middle mouse buttons. Also improve ability to click things in low FPS situations.
This introduces a lot of breaking changes:
Backends/integrations now pass mouse events via the even stream.
Response has an interface of mostly methods instead of public members.
input.mouse is now input.pointer and has new interface.
* Rename 'mouse' to 'pointer' everywhere (pointer = mouse or touch)
* Make Response::clicked and Response::double_clicked into methods
* Remove Response::active and add dragged() and interact_pointer_pos()
* Support multiple mouse buttons
* Make PointerState interface all methods
* Make most members of Response private
## 0.5.0 - 2020-12-13
### Added ⭐
* Emoji support: 1216 different emojis that work in any text.
* The Demo app comes with a Font Book to explore the available glyphs.
* `ui.horizontal_wrapped(|ui| ...)`: Add widgets on a row but wrap at `max_size`.
* `ui.horizontal_wrapped_for_text`: Like `ui.horizontal_wrapped`, but with spacing made for embedding text.
* `ui.horizontal_for_text`: Like `ui.horizontal`, but with spacing made for embedding text.
* `egui::Layout` now supports justified layouts where contents is _also_ centered, right-aligned, etc.
* `ui.allocate_ui(size, |ui| ...)`: Easily create a child-`Ui` of a given size.
* `SelectableLabel` (`ui.selectable_label` and `ui.selectable_value`): A text-button that can be selected.
* `ui.small_button`: A smaller button that looks good embedded in text.
* `ui.drag_angle_tau`: For those who want to specify angles as fractions of τ (a full turn).
* Add `Resize::id_source` and `ScrollArea::id_source` to let the user avoid Id clashes.
### Changed 🔧
* New default font: [Ubuntu-Light](https://fonts.google.com/specimen/Ubuntu).
* Make it simpler to override fonts in `FontDefinitions`.
* Remove minimum button width.
* Refactor `egui::Layout` substantially, changing its interface.
* Calling `on_hover_text`/`on_hover_ui` multiple times will stack tooltips underneath the previous ones.
* Text wrapping on labels, buttons, checkboxes and radio buttons is now based on the layout.
### Removed 🔥
* Removed the `label!` macro.
