Population of the global CSS declarations

[kouralex]

Whilst implementing a plugin I ran into issues related to the way CSS is used and declared in Skosmos.

It appears that there are quite a few rules declared in styles.css that are so general that they override the default declarations for common elements, which causes trouble when one wants to render the content of the widget as is. An easy fix would be to encapsulate every global CSS declaration to some specific container.

The problem is also focused around the libraries used, however, I do not have a simple solution for them in my mind.

[kouralex]

Made some improvements in referencing commits especially to table css declarations; however, we are still missing proper handling of fonts etc.