Now it's easier to change the investments filter. Previously we had to
go back to the budget index page, change the filter there, and then
select one heading.
Now the links to change the current filter in the budget index page
aren't needed anymore.
Having the date at the beginning makes it less weird to select a custom
date now that we don't have enough space to display the "from" and "to"
date selectors in different columns.
Now the banner component accepts either a banner or a section and loads
the banner if it's a section, so we don't have to add the `@banners`
variable in several controllers.
