* Replace first Windows occurence with trademarked entity
* Add trademark info for Microsoft Windows and Symantec Ghost.
* Replace "FreeBSD" with &os; and "ports collection" with &ports;,
to keep the capitalization consistent. Also introduce an &os.ports;
entity, which expands to "FreeBSD Ports Collection", to uniformly
refer to the Ports
* Add <emphasis>, <application> and <quote> tags here and there
* Use manpage entities, instead of <literal> for FreeBSD
command-line utility references
* Various minor grammar and syntax nits
