* adjusted past_format and future_format to past_tense and future_tense

* corrected all tests and documentation to reflect new keyword argument names
* changed example _tense strings to use {} instead of {0}
* cleaned up docstrings

test_ago.py

@@ -41,17 +41,17 @@ def test_one_day_singular():
 def test_two_day_plural():
     assert 's' in delta2human( timedelta(2) )
 
-def test_past_format():
+def test_past_tense():
     output = human( PAST,
-      past_format = 'titanic sunk {0} ago',
-      future_format = 'titanic will sink in {0} from now'
+      past_tense = 'titanic sunk {} ago',
+      future_tense = 'titanic will sink in {} from now'
     )
     assert 'titanic sunk' in output
 
-def test_future_format():
+def test_future_tense():
     output = human( FUTURE,
-      past_format = 'titanic sunk {0} ago',
-      future_format = 'titanic will sink in {0} from now'
+      past_tense = 'titanic sunk {} ago',
+      future_tense = 'titanic will sink in {} from now'
     )
     assert 'titanic will sink in' in output
 
@@ -69,11 +69,11 @@ def test_output():
     print '\nTesting past:\n'
     print delta2dict( PAST_DELTA )
     print 'Commented ' + delta2human( PAST_DELTA, 3 )
-    print human( PAST, past_format = "Commented {0} ago" )
+    print human( PAST, past_tense = "Commented {} ago" )
 
     print '\nTesting future:\n'
     print delta2dict( FUTURE_DELTA )
     print 'Shutdown ' + delta2human( FUTURE_DELTA, 3 )
-    print human( FUTURE, future_format = 'Shutdown in {0} from now' )
+    print human( FUTURE, future_tense = 'Shutdown in {} from now' )
     print ''