Test against the latest version of 1.5.X and the newly released 1.6.
Fix some uses of default_error_messages
Fix REGON validation.

- There is a special case when the result of modulo 11 division equals 10.
  In this case, the correct checksum is 0. Taken from:

      http://wipos.p.lodz.pl/zylla/ut/nip-rego.html#regon
Merge pull request #62 from krisb78/master

Resolve issue in Polish REGON validation
Remove unused gender argument from CZBirthNumberField.clean
Add normalization to Lithuanian (lt) postal code field

Both "12345" and "LT-12345" now get normalized to "LT-12345", like the
Latvian postal code.
Merge pull request #69 from intgr/lt

Add normalization to Lithuanian (lt) postal code field
Merge pull request #67 from intgr/cz

Remove unused gender argument from CZBirthNumberField.clean
Add Latvian (lv) flavor with Latvian municipalities

110 municipalities and 9 republican cities.

Translations will come later.
Add Latvian (lv) postal code field (LV-XXXX)
Add Latvian (lv) personal code field (XXXXXX-XXXXX)
Add Estonian (ee) flavor with zipcode, counties and personal ID code fields
Merge pull request #70 from intgr/ee

Add Estonian (ee) flavor with zipcode, counties and personal ID code fields
Merge pull request #68 from intgr/lv

Add Latvian (lv) flavor: postal code, personal code and municipality fields
doc: Finland not Finnland
Merge pull request #71 from intgr/fi

doc: Finland not Finnland
Add test directory to $PYTHONPATH during tests

Fix for #49
Merge pull request #72 from django/issue-49

Add test directory to $PYTHONPATH during tests
Extended the documentation about how to run tests.
Updated test requirements.