Rename wombat iTerm2 color scheme to wombat256.
Update bright colors; change selection to yellow.

Bright colors were previously arbitrarily set; they are now all exactly
25% brighter than their normal counterparts.
Use Normal bg color instead of black for fg.
Add monokai and monokai256 iTerm2 color schemes.
Add custom pretty format; default to --no-prompt.
Reverse title colors; use default bg for fg.