[Tagging] Manor tagging

[Daniel Koć]

Since there was no response so far, may I propose to deprecate using 
historic=manor and suggest on the wiki page to use only historic=castle 
+ castle_type=manor instead. The reasons:

1. I can't see the difference in what both schemes try to symbolize.

2. There's a section on historic=manor wiki that says:

"There may sometimes be problems distinguishing between manors, castles, 
stately homes. The manor tag is intended only for representative 
buildings that are in the same time the administrative center of a large 
agricultural estate. Buildings lacking this economic feature should not 
be tagged."

Being a subtype of castle shows that distinction is softer than when 
using a separate tag.

3. It's easier for data consumers (including rendering) to have more 
general categories with subcategories.

4. It would be similar to historic=palace situation (historic=castle + 
castle_type=palace is documented and used more than this).

-- 
"My method is uncertain/ It's a mess but it's working" [F. Apple]