Move Redis collections iterators in a different namespace.

The base iterator class is now known as RedisCollectionIterator and
we've also renamed a few methods to make their naming more generic.

tests/Predis/Collection/Iterator/HashIteratorTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Predis\Iterator\Scan;
+namespace Predis\Collection\Iterator;
 
 use \PHPUnit_Framework_TestCase as StandardTestCase;
 

tests/Predis/Collection/Iterator/KeyspaceIteratorTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Predis\Iterator\Scan;
+namespace Predis\Collection\Iterator;
 
 use \PHPUnit_Framework_TestCase as StandardTestCase;
 

tests/Predis/Collection/Iterator/SetIteratorTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Predis\Iterator\Scan;
+namespace Predis\Collection\Iterator;
 
 use \PHPUnit_Framework_TestCase as StandardTestCase;
 

tests/Predis/Collection/Iterator/SortedSetIteratorTest.php

@@ -9,7 +9,7 @@
  * file that was distributed with this source code.
  */
 
-namespace Predis\Iterator\Scan;
+namespace Predis\Collection\Iterator;
 
 use \PHPUnit_Framework_TestCase as StandardTestCase;