Get errors and notices in the theme class, not the header itself.
The specific font-family belongs in our custom stylesheet, not the generic one.
Switch from a couple of static CSS files to several modular LESS files.
Replace the bootstrap alert classes with our new ones.
Remove a defunct StackItem.
Remove namespaces when applying formatters, they are handled in the Format class now.
Do not import anything in our individual LESS files.
Remove all the variables from the alerts LESS.
Make sure the assets cache directory exists, but everything is ignored.