Added link to status-effects.xml

Also removed the duplicate link to maps.xml.
Changed set tag to skill-set and special-set
Merge pull request #5 from atheros/skills-specials-set

Changed set tag to skill-set and special-set
Added initial description of new settings.xml file
attributes.xml also has points tag
Fixed a bunch of links to the download page

Which changed from /downloads to /downloads.html due to using static
site now.

Might be worth looking into dropping those extensions.
Fixed typo
Added forum link
Added documentation of warp object
Fixed missing ] in a link
Fixed link to subdirectory