Remove inline qualifiers inside .cpp

Use of inline in the .cpp file causes link errors with gcc.

Conflicts:
	imgui.cpp

InputInt() also hexadecimal input (awkwardly via ImGuiInputTextFlags_CharsHexadecimal but we will allow fmt string in InputInt* later)

+ Fix for large ints constant assignment

InputInt() doesn't cast to float, fix handling lost of precision with large integer. Added primitives to support more data types.

Conflicts:
	imgui.cpp

Slider: fixed using FramePadding between frame and grab visual. Scaling that spacing would look odd.

imgui_demo.cpp doesn't redefine functions from imgui_internal.h so all files can be unity-built (#219)

Examples: DirectX11: Clear font texture view pointer to ensure Release() doesn't get called twice

Conflicts:
	imgui.cpp