v1.53.1: Make struct ImFontConfig match imgui's.

Fixes problems using custom fonts.

v1.53

based on https://github.com/ocornut/imgui/releases/tag/v1.53

v1.52.1: revert missing ImFontConfig_DefaultConstructor, fix fn name ImFont_Ge…

reintroduced ImFontConfig_DefaultConstructor see #14

v1.52

based on https://github.com/ocornut/imgui/releases/tag/v1.52

v1.51

based on https://github.com/ocornut/imgui/releases/tag/v1.51

v1.50.1

ImGuiListClipper type added

update to imgui 1.50

add missing new param

was introduced in 1.50

v1.49

release based on the imgui release tag 1.49: https://github.com/ocornut/imgui/releases/tag/v1.49

v1.48

release based on the imgui release tag 1.48: https://github.com/ocornut/imgui/releases/tag/v1.48

v1.47

release based on the imgui release tag 1.47: https://github.com/ocornut/imgui/releases/tag/v1.47