Rename PHPUnit's config file (#433)

Usually, we use phpunit.xml.dist config files and allow developers overriding
them with their own phpunit.xml (if necessary) which is part of the .gitignore

Also sorting entries of .gitignore alphabetically.

Author: rtucek

.gitignore

@@ -1,7 +1,8 @@
+/.buildpath
+/.project
+/.settings
 /vendor
-composer.phar
 composer.lock
+composer.phar
 Thumbs.db
-/.settings
-/.buildpath
-/.project
+phpunit.xml