Release 5.7.2

[mundschenk-at]

Changes proposed in this pull request:

• Updates build dependencies (Grunt & Composer).
• Fixes tests to work with Brain Monkey 2.5.x.
• Updates Travis-CI & Scrutinizer-CI settings.
• Adds unit test for WP_Typography\Implementation::init_settings_from_options.
• Adds set_dewidow_word_number( 1 ) when converting options to PHP-Typography settings (fixes #288).
• Uses process_feed filter for link_name and term_name (fixes #287).