[Toybox] debian xxd

[enh]

today in "why does debian keep changing things under me?" and "man
shakes fist at yet another tool adding unhelpful coloring", i wasn't
happy to see what just happened to debian xxd... and i'm the one who
added coloring to toybox hexedit. i just can't make sense of why
anyone would want the xxd coloring --- it's way too distracting:

0x00 - white
isspace(ch) - yellow
most other control characters - red
isgraph(ch) - green
0xff - blue

(if that doesn't sound bad, trust me it's terrible in practice.)

needless to say, i won't be adding that to toybox xxd ... and i'll be
sad if anyone else does :-(