Make some changes to the ACPI section:

• Document the ``Shortcomings'' of APM in the ACPI section.

	  This was missed when the section was originall committed.

• Change section title to: ``Power and Resource Management''

	  because it is a bad idea to use acronyms and abbreviations
	  in a chapter or section title, as it can lead to confusion.

• While I am there, add a missing </sect2> tag.

Approved by: des (mentor)