Fixed typo and moved glossary section.

Moved the glossary section to a point that corresponds roughly to
where it occurs in the other ARIA documents.
Modified terminology section.

For "append the result to X", made entries for appending with and
without a space.  Also, added entries for "prepend the result to X".
ISSUE-435:  Added AXAPI Mapping for role="text".
Used new prepend/append terms within algorithm.

Tweaked the definitions of the prepend/append terms, and applied
them as appropriate in various steps of the computation.
Reworded label and description mappings to use the plural form.

Changed the accessible name and description mappings to handle
situations where aria-labelledby and aria-describedby reference
muliple nodes.  As such, changed the language from the singular
form "pointer" to the plural form "pointers".
Modified step 2A of the text alternative computation.

Added that a native host language element or attribute that is
used for text alternatives, and is referencing the current node,
has the same effect as aria-labelledby and aria-describedby in
terms of overriding skipping hidden nodes.
Added clarification and editorial note.

Regarding override of hidden nodes:  clarified that the native
host language element or attribute references the current node.

Added an editorial note to step 2B that aria-describedby is
processed in a similar way to how aria-labelledby is handled.