Add fund_type field to operating-unit-index.json.

Modified undp-process-xml.py to add a fund_type field to
operating-unit-index.json.  Ran the new script on the data in the
downloads/ zip file, producing a new operating-unit-index.json in the
api/ directory.
Remove unzipped data from downloads/ directory.
minor edits to undp-process-xml.py.
Use new operating-unit-index.json
Add fund_type to model and color map according to different fund types
Revert api data to before adding fund_type
Remove some logging code
Add opacity to map
Add legend to map
add legend position css
Show/hide legend when switching map layers
Let process overwrite operating-unit-index.json
Merge pull request #58 from undp/fund_type

Fund type