Add option to avoid use of custom fonts (assets)

[ssbarnea]

The default behaviour of the report generator is to to make use of a set of huge assets due to the use of custom fonts. That add ~3MB to any zip archive and is a huge waste of space.

It would be useful if we would have an option to avoid that and refer to google web fonts or similar, so we would avoid having to add those fonts.

Basically I care less about fonts used, but I would like to produce an HTML report that does not need those very big extra files.

[adamgruber]

Have a look at the cdn option. Setting this to true will load JS/CSS via remote links and not output any additional assets.