Add colours to output

[lelutin]

Add a means to colourize the output to sys.stdout. It should take the form of an API that the actions can use or simply enable (and then the tomtom classes would call upon the necessary functions to add colour markup.

Examples of uses:

• search -- colourize the note name and the line in two different colours. also mark the searched term to make it stand out.
• list -- colourize the changed-date, the note name and the tags in different colours.
• display -- colourize the note name and the tags in different colours. the separator between notes should also be made to stand out.