A few terms I'd like to see in perfbook's Glossary

[Akira Yokosawa <akiyks@xxxxxxxxx>]

Hi Paul,

While reading through Section 9.5.4, I noticed a few terms
I'd like to see in perfbook's Glossary.

 - Reference Counter/Counting
 - Existence Guarantee
 - Type-safe Memory

"Reference counter" is already mentioned in a couple of existing
items in the glossary.

"Existing guarantee" might be obvious enough and not worthy
to be in the glossary.

Thoughts?

There were only a few minor nits in the section.
Will post a patch taking care of them.

        Thanks, Akira