Editorial: uniformize list-based "or"s and "and"s

We have used a variety of styles and introductory wordings. This tries to settle on

> if one|all of the following are true:
>
> * condition1;
> * condition2; or
> * condition3

This also brings along various small fixes in related areas, such as inserting <p> tags, changing the complete getter steps to modern style, and fixing one <ol> that should have been a <ul>.