omar/imgui: Release v1.20
Mostly fixes.
- Fixed InputInt() InputFloat() label not declaring their width, breaking usage of SameLine().
- Fixed hovering of combo boxes that extend beyond the parent window limits.
- Fixed text input of Unicode character in the 128-255 range.
- Fixed clipboard pasting into an InputText box not filtering the characters according to contents semantic.
- Dragging outside area of a widget while it is active doesn't trigger hover on other widgets.
- Activating widget bring parent window to front if not already.
- Checkbox and Radio buttons activate on click-release to be consistent with other widgets and most UI.
- InputText() nows consume input characters immediately so they cannot be reused if ImGui::Update is called again with a call to ImGui::Render(). (fixes #105)
- Examples: Console: added support for History callbacks + some cleanup.
- Various small optimisations.
- Cleanup and other fixes.
