feature #4655 Document new progressbar methods (javiereguiluz)

This PR was merged into the 2.6 branch.

Discussion
----------

Document new progressbar methods

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.6+
| Fixed tickets | #4593

Commits
-------

6a3cbd9 Changed the "new in Symfony 2.6" message for consistency
2b86d80 Documented getProgress/setProgress methods

Author: weaverryan

components/console/helpers/progressbar.rst

@@ -42,7 +42,10 @@ number of units, and advance the progress as the command executes::
 Instead of advancing the bar by a number of steps (with the
 :method:`Symfony\\Component\\Console\\Helper\\ProgressBar::advance` method),
 you can also set the current progress by calling the
-:method:`Symfony\\Component\\Console\\Helper\\ProgressBar::setCurrent` method.
+:method:`Symfony\\Component\\Console\\Helper\\ProgressBar::setProgress` method.
+
+.. versionadded:: 2.6
+    The ``setProgress()`` method was called ``setCurrent()`` prior to Symfony 2.6.
 
 .. caution::
 
@@ -300,10 +303,13 @@ that displays the number of remaining steps::
     ProgressBar::setPlaceholderFormatterDefinition(
         'remaining_steps',
         function (ProgressBar $bar, OutputInterface $output) {
-            return $bar->getMaxSteps() - $bar->getStep();
+            return $bar->getMaxSteps() - $bar->getProgress();
         }
     );
 
+.. versionadded:: 2.6
+    The ``getProgress()`` method was called ``getStep()`` prior to Symfony 2.6.
+
 Custom Messages
 ~~~~~~~~~~~~~~~