Enable basic customization

Right now most of plot/publish/etc options are hardcoded. New options can easily added to PlotOptions/PublishOptions via **kwargs.

• tagplot: custom position and rotation of ID
• tagplot: font, fontsize and color of the ID
• tagplot: handle already installed fonts (system defaults, etc.)
• tagplot: document usage of custom fonts
• tagplot: qrcode position and size
• tagplot: allow to hide ID and print only qrcode

Please add suggestions in the issue. We can add them to the list then.