Clean up of unused variables

There are few unused variables in the below files:
includes/features.taxonomy.inc
Unused variable $name.

includes/features.locale.inc
Unused variable $key.

includes/features.menu.inc
Unused variable $key.

includes/features.field.inc
Unused variable $key.
Unused variable $translatables.

includes/features.node.inc
Unused variable $name.

features.export.inc
Unused variable $j.
Unused variable $k.
Unused variable $components.

features.module
Unused variable $component.

features.drush.inc
Unused variable $k.
Unused variable $features_to_revert.

features.admin.inc
Unused variable $module_name.
Unused variable $tar.
Unused variable $revert.