Fix Colors in Windows

[jsbueno]

Current terminal backend uses the "39 SGR" Ansi sequence for 24bit color on the terminal. However, colorama wll simply strip these sequences off, resulting in no color capabilities in windows - even though windows terminal suppots 24bit color, and "cmder" supports the color sequences (and rounds the colors down to the 16 more used values).

Find a way to detect the terminal app under windows, and only trigger "colorama" if on "cmd" - the other apps work with plainANSI sequences.
Round colors down to the 16 "well known codes" if on cmd or cmder.