* Bug Fixes
* Fixed `AttributeError` in `rl_get_prompt()` when prompt is `None`.
* Fixed bug where using choices on a Settable didn't verify that a valid choice had been entered.
* Fixed bug introduced in cmd2 2.0.0 in which `select()` converts return values to strings. It should never
have converted return values.
* Enhancements
* Added settings to Column class which prevent a table from overriding existing styles in header
and/or data text. This allows for things like nesting an AlternatingTable in another AlternatingTable.
* AlternatingTable no longer automatically applies background color to borders. This was done to improve
appearance since the background color extended beyond the borders of the table.
* Added ability to colorize all aspects of `AlternatingTable`, `BorderedTable`, and `SimpleTable`.
* Added support for 8-bit/256-colors with the `cmd2.EightBitFg` and `cmd2.EightBitBg` classes.
* Added support for 24-bit/RGB colors with the `cmd2.RgbFg` and `cmd2.RgbBg` classes.
* Removed dependency on colorama.
* Changed type of `ansi.allow_style` from a string to an `ansi.AllowStyle` Enum class.
* Deprecations
* Deprecated `cmd2.fg`. Use `cmd2.Fg` instead.
* Deprecated `cmd2.bg`. Use `cmd2.Bg` instead.
* Breaking Changes
* To support the color upgrade, all cmd2 colors now inherit from either `ansi.FgColor` or `ansi.BgColor`.
Therefore, `ansi.style()` no longer accepts colors as strings.