Overrode the base font size to 16px in the bootstrap CSS

This was done the "ugly" way, by overriding every instance where the value of the variable `@font-size-base` was used, so that work on the CSS can proceed with the correct font sizes until the ideal way can be implemented.

The ideal way would be to modify the build process to build `bootstrap-min.css` from the `.less` files instead of simply copying the pre-built one from the `dist` folder of the bootstrap dependency. That way the build could override the default `variables.less` with our own copy that would contain our own values and build `bootstrap-min.css` from that. I will investigate how to accomplish this.