Remove unused definitions of terms 'formal argument', 'actual argument', and
'actual parameter'. Unify uses of 'formal parameter' and 'parameter' to all use
the vastly more common term 'parameter' and remove the definition of 'formal
parameter'.
Tighten the words we use in "Throughout this [sub]clause" wording
to introduce a set of requirements for template arguments based
on their names, and make these paragraphs consistent.
Fix vertical whitespace around grammar definitions and bullets.
Remove trailing blank lines at ends of grammar productions.