cleaned up svn entries and rolled to latest version
recompiled latex doc and updated pdf files
minor editing
Update data_exchange.py
update pdf directory
fixes in DataExchange-example5.py
fixed the \exchange\data\data problem
fixed python examples /exchange/data/data issue
Added new data_exchange entries.
Merge branch 'master' of https://github.com/data-exchange/data-exchange
Added data_exchange entry deifnitions
Added an entry for amplifier under /measurement/instrument.