4.0.0-rc.2

First some notes in respect to the users of the beta versions:

You may be wondering why a major version is being released as a preview again. I'm using the library myself in other projects and have noticed that finding appropriate file type extensions for given Internet Media Type strings is more complicated than necessary.

Unfortunately big changes of the public interface were required to fix this issue. I think the best way to deal with this was to release the changes as soon as possible to upset as few users as possible. I apologize. (The release version is coming soon.)

Project reference: On some systems, the content of the CHM file in the Assets is blocked. Before opening the file right click on the file icon, select Properties, and check the "Allow" checkbox - if it is present - in the lower right corner of the General tab in the Properties dialog.