npmlog writes colors regardless of --no-color option

npm original behaviour is: 

- `npm --color` will always write coloured output
- `npm --no-color` will write output with no vt escape sequences
- `npm` without any options above will write output depending on `process.stderr.isTTY`

Forked npmlog always write colors, no way to turn off them.

Same for search output... maybe bring `ansi` back? Only thing `chalk` is used for is underline, and ansi can do that (also providing a global color-off switch and other stuff).