improve display of Mappings

[VladimirAlexiev]

The display of Mappings is horrible and useless:

• lots of wasted space
• repeated "This is the mapping for the Wikipedia template..." for nested mappings (I think there's a param like header=no, but nobody uses it)

Eg compare

• display: http://mappings.dbpedia.org/index.php/Mapping_bg:Монарх
• source: http://mappings.dbpedia.org/index.php?title=Mapping_bg:Монарх&action=edit

The display is incomprehensible. It'd be better to just display the source (but how)?

Currently the only use of the display is to show that you haven't made a nesting or other syntax error

[VladimirAlexiev]

This pic from http://vladimiralexiev.github.io/pres/20150209-dbpedia/dbpedia-problems-long.html#sec-5-1 illustrates the issue:

• left is "display": useless
• right is "source": ok
• bottom is "diff": quite useful