Added handling to only define used rfc2119 terms

Addresses the issues presented in #345
Fixed formatting of else clauses
Added braces to scope if clauses.
Added a note about how the counter is not used.
Merge pull request #346 from w3c/patch-345

Added handling to only include references to used rfc2119 terms.

Fixes #345.
v3.2.22
Merge branch 'develop' into gh-pages