Changes  committed:

	new file:   Data/cf-standard-names/26/src/area-type-table.xml
	new file:   Data/cf-standard-names/26/src/cf-standard-name-table.xml
	new file:   Data/cf-standard-names/27/src/area-type-table.xml
	new file:   Data/cf-standard-names/27/src/cf-standard-name-table.xml
	modified:   documents.md

Adding versions 26 and 27 of standard name table xml following reorganisation
of the CF repositories.
Adding area_types table (version 2).
Fixing dead links to previous xml versions of standard name table from
Documents page.

J A Pamment 24 July 2014