CD-ROM, FTP, CTM, and CVSup. Adjust cross-references accordingly.
Add a list of CVSup mirror sites, and reference it from the CVSup
tutorial.
Also, fix a spelling error in the porting document.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
pointed out by Rick Robinson. Found and fixed some grammar problems
at the same time.
Note: the reason for avoiding contractions is two-fold:
1) It makes the text easier to understand for people who speak English
as a second language.
2) Expanding the contractions often reveals poorly worded passages.
