DrawList: apply current pixel density to DrawList's fringe scale. Added ImDrawList::_SetPixelDensity(). Reword FontRasterizerDensity as CurrentPixelDensity.

Amend 94a4322.

# Conflicts:
#	imgui.cpp
#	imgui.h
#	imgui_draw.cpp
#	imgui_internal.h
5 files changed