Renamed national field in Location model to island.

National was originally added to support NUTS Level II designations
specifically for Madeira and Azores in Portugal. However these are
also (autonomous) regions so a more useful field to have would be
island so that sightings on island groups can easily be distinguished.
Rather than add more migrations since national was added in migration
33 it was easier to rename the field.
Renamed EntryStatus to EntryTag.

Modified the existing migrations instead of adding a new one.
Updated species names and occurrence in Portugal.

Also minor changes to standard names and corrected a few missing accented
characters.
Updated occurrence with species and groups for the western palearctic.
Entry description defaults to an empty string if not specified.
Fixed errors in setting up the demo project.
Updated load_checklists command based on experience loading real data.

In eBird when entering a checklist a protocol such as Stationary, Traveling,
etc. must be specified. For each protocol a time of the observation is
given. However it looks like the time is either not required or the value
is being omitted from the data obtained via the API or web page. Updated
the model so the time field on Method may be null.

Updated the various find methods in load_checklists so the error messages
generated when an object cannot be found in the Map (which maps names in
the checklist data to types in the model) give the name and model that was
being looked up.

The load_checklists command no longer uses the common name when looking up
a Species. Now only the standard name and scientific names are used. This
avoided case where the standard name and common name matched different
subspecies, the canonical example being Green-winged Teal which is the
standard name for Anas crecca but the common name for Anas crecca carolensis.
Updated internationalization of field names in recent migrations.
Updated .gitignore to leave out any databases added for demos etc.
Moved reference data used to initialize database into the checklists package.

The data was split into separate files which are then loaded and merged to
generate a final file which contains names for the difference languages
defined in the LANGUAGES setting before being loaded into the database.
The data is loaded using scripts called from django_extensions runscript
management command.

Updated reference data documentation to reflect changes.

Updated setup so data will be included in a source distribution. That makes
it a lot easier to initialize the database when the app is installed from
PyPI.
Cleaned up species lists so standard_names and scientific names match clements.

Updated the species lists for Portgual, Açores and Madeira and the list for
the Western Palearctic so the standard_names and scientific_names match those
in initial.csv which is the master species list created from the Clements
checklist.

Updated or create corresponding lists for species groups from the species
lists.
Added scripts to simplify managing the species lists.