Terminal color tweaks. (#201)

* Add KiTTY configuration (manually; could potentially use
  https://github.com/stayradiated/termcolors/pull/17/ in the future)
* Tweak foreground/background/white/black colors to be visually distinct
  from one another

Closes #200.

term/One Dark.Xresources

@@ -4,8 +4,8 @@
 *.cursorColor:  #ABB2BF
 
 ! black
-*.color0:       #282C34
-*.color8:       #3E4452
+*.color0:       #5C6370
+*.color8:       #4B5263
 
 ! red
 *.color1:       #E06C75
@@ -33,5 +33,5 @@
 
 ! white
 *.color7:       #ABB2BF
-*.color15:      #5C6370
+*.color15:      #3E4452