0.19.0

Main changes:

• d4b7246 Fix additional empty worksheet in excel creation (Fabio Daniele)
• ce5004f Fix bug which doesn't delete the row after iteratorion (Markus Bachmann)
• 2870f94 ExcelWriter: Optimize code at writeItem() (Igor Mukhin)
• 9a8fef6 ExcelWriter: Added option to prepend header row with column names (Igor Mukhin)
• d27a581 CsvWriter: Added option to prepend header row with column names (Igor Mukhin)
• 5726169 Add BatchWriter (Baachi)
• b7a2484 Workflow implements LoggerAwareInterface and Trait (Sági-Kazár Márk)
• 7b79829 Removes fluent interface from writer methods (Sági-Kazár Márk)
• 7c263de Adds tests for iterator readers (Sági-Kazár Márk)
• 89ab731 Adds IteratorReaders (Sági-Kazár Márk)
• f028439 Replaces SplObjectStore with array in Steps (Sági-Kazár Márk)
• efe2891 Adds WriterTemplate trait instead of AbstractWriter (Sági-Kazár Márk)
• 6f28633 Adds editorconfig (Sági-Kazár Márk)
• 3dc53a3 Some in-code improvements: use sprintf, PHP 5.4 array notation (Sági-Kazár Márk)
• 2599f48 Docblock improvements, removing inconsistency (Sági-Kazár Márk)
• a07d322 Merge pull request #177 from igormukhingmailcom/pcntl (David de Boer)
• 56aabc7 Proper reaction for SIGTERM and SIGINT (Igor Mukhin)
• b0122a5 Switch to PSR-4 (David de Boer)
• 9751e1d Introduce steps (Markus Bachmann)
• 10e2409 DoctrineWrite fix for issue #194 (Justus Krapp)
• 45069d8 Merge pull request #193 from ip512/master (David de Boer)
• a01d235 Add version 2.4 requirement for doctrine (Gregory Pelletier)
• 2292ef2 Change EntityManager to EntityManagerInterface (Gregory Pelletier)
• 1e14c81 Added DateTimeToStringValueConverter and its test. Updated README. Added phpunit to composer.json (Mateusz Zalewski)