Require parens around mixed boolean expressions

[kastermester]

To avoid misunderstandings when writing code, and aid readability when reading code, the following expressions:

(exprA || exprB && exprC);
(exprA && exprB || exprC);

Must be written as:

(exprA || (exprB && exprC));
((exprA && exprB) || exprC);

Obviously it is also valid to write them as:

((exprA || exprB) && exprC);
(exprA && (exprB || exprC));

The idea here is to avoid any possible confusion around precedens in the operators.

Other cases that needs taken care of are most welcome additions to this issue.