Website changed from HTML 4.01 to XHTML 1.0

[Harold L Hunt II]

I have translated all of the hand-generated files on the Cygwin/X 
website (http://x.cygwin.com/) from HTML 4.01 Transitional to XHTML 1.0 
Transitional.

I used Tidy UI to do this.  Tidy UI just provides a nice interface in 
Windows to HTML Tidy, which cleans up and translates HTML.  Tidy UI can 
be obtained here:

http://users.rcn.com/creitzel/tidy.html#tidyui

Let me know if anything seems messed up on the website.  Be aware that 
the documentation (FAQ, User's Guide, and Contributor's Guide) are 
generated from DocBook and are thus not part of this conversion.

Harold