Let WP translates "save"

In each version on WP this term is translated.
Merge pull request #520 from TweetPressFr/patch-1

Let WP translates "save". Props @TweetPressFr
Update init.php
Update cmb_Meta_Box_field.php

Sets default values for date and time formats
Update cmb_Meta_Box_types.php

Uses custom date and time formats or the default one if none is provided.
Update readme w/ new date/time format option
Add todo item for passing data attributes to JS
Make `image_id_from_url` a static method. Closes #509
update readme
Remove debug code
Fixes issue where remove file button wasn't clearing the url field. Fixes #514
Add issue/PR tags to readme changelog
Remove wysiwyg wp_editor id hack
Add nonce only once per page. Closes #521
Fix typo
Simplify wysiwyg escaping and allow it to be overridden.
Update readme
Add 'Select/Deselect All' button for multicheck
Merge branch 'trunk' of github.com:WebDevStudios/Custom-Metaboxes-and-Fields-for-WordPress into trunk