Change the style, color, size of each chordpro component

[edwinzap]

Now, if I change the text size, only the whole content size change.

• I would like to be able to choose a different size and style (bold/italic) for each components of a chordpro: meta, chord, tab, title, subtitle.
• I would be nice to be able to choose also the color of these components

Extended features

• Add a reset button to come back to the default style
• Set the style per song
• Modify the default style in the settings