v0.5.0

Added

• Support for ConfigFlags::RENDERER_HAS_VTX_OFFSET in imgui-glium-renderer
  and imgui-gfx-renderer. This makes it possible to output large meshes (e.g.
  complex UIs) without problems when using these renderers
• Ui::begin_tooltip to support using tooltips with stack tokens instead
  of closures
• API for accessing the background drawlist
• Tab bar / tab item API
• Redesigned drag slider API

Changed

• Upgrade to cimgui / imgui 1.78
• Store per-texture sampler parameters in imgui-glium-renderer to support
  customizing them
• Slider widget constructors no longer require the range parameter. Call the
  range function on the builder to set the range.

Fixed

• Reduce unnecessary winit cursor changes which earlier caused cursor
  flickering or invalid cursors on some platforms (at least Windows)

Removed

• Various things that were deprecated in imgui-rs 0.4.0