Obsolete variables and outdated Gnus guides

[Björn Bidar]

Hello,

Recently I noticed some variables in my Gnus config which where no where 
defined.
I think, I copied them during my initial configuration from a guide or someones
config.

The variables are:
- gnus-article-decode-mime-words :: unbound -> It is a function, removed with 
Semi Gnus. Is it used these days?
- gnus-article-decode-charset :: unbound same
- gnus-mime-view-all-parts :: unbound but there is also function under the same 
name

Where these ever a thing or is this just a case of copying someones
else errors? The variable or function to decode mime feels especially
outdated.

Have a great week,

Björn