Part of the work to make it easier to tests of diff output. Specifically, we now allow users to pass --color=option for several pulumi commands. 'option' can be one of 'always', 'never', 'raw', and 'auto' (the default).
The meaning of these flags are:
1. auto: colorize normally, unless in --debug
2. always: always colorize no matter what
3. never: never colorize no matter what.
4. raw: colorize, but preserve the original "<{%%}>" style control codes and not the translated platform specific codes. This is for testing purposes and ensures we can have test for this stuff across platform.