Skip %+ and %# format flags for scanning

[idbrii]

Fix typed in values are ignored when SliderInt's format specifier includes the + flag:

+: the sign of signed conversions is always prepended to the result of
the conversion (by default the result is preceded by minus only when it
is negative)

Also skip the # flag since it seems valid to use (esp. for octal and hex):

# : alternative form of the conversion is performed. See the table
below for exact effects otherwise the behavior is undefined.

There are two additional unhandled flags that only affect padding:

• and space. Formatting flags don't make sense in a SliderInt's format string, so I've omitted them.

Test

In this example, editing the value by dragging it to +80º works but when Ctrl-clicking and typing in 10 it reverts to the previous value after hitting Enter:

	if (ImGui::Begin("Hello"))
	{
		static int val = 0;
		ImGui::SliderInt("Slider", &val, 0, 100, "%+dº");
		ImGui::End();
	}

[ocornut]

Merged as cac76b2, thank you very much !