changed country name directories

Changed the country name directories (just “Netherlands” in fact) to
ISO 3 standards. See:
http://unstats.un.org/unsd/tradekb/Knowledgebase/Country-Code
moved country files for the Netherlands to NLD

Moved the country files for the Netherlands to the folder NLD, after
changing the country folders to ISO-3 names.
added OCC2000 to ISCO-88 files

Added OCC2000 to ISCO-88 codes from the “Changing patterns of
occupational segregation in Great Britain and the USA” project hosted
by the Centre for Longitudinal Studies
http://www.cls.ioe.ac.uk/page.aspx?&sitesectionid=351&sitesectiontitle=O
ccupational+segregation#
added India National Classification of Occupations

These files describe NCO2004 and their relation to earlier schemes in
India and some notes on ISCO-88. Originates from the Directorate
General of Employment & Training
Ministry of Labour Government of India:
http://dget.nic.in/nco/welcome.html