add event handler for keypress
Merge pull request #6 from huda123/master

Make enter button submit the form.
Add dashboard page to manage plugin options
dashboard: handle warning for undefined variables, add missing form tag
dashboard: handle warning for undefined variables
dashboard: add method to form tag
Dashboard page: fix "for" attribute in label tag
Dashboard menu: add form to add newsletters, and table to view newsletters
Dashboard menu: remove value attribute from newsletter form elemenets
Dashboard menu: fix wrong $_POST key for newsletter_key
Display newsletters as checkboxes in the front-end
Add spaces between newsletter name and the label surrounding it
surround input text and checkboxes with form tag, make form submission trigger the ajax call
Merge branch 'feature/extract-variables-to-options-page' of github.com:HaykalMedia/Re-Subscribe into feature/extract-variables-to-options-page

Conflicts:
	src/Resubscribe.php
JS: prevent form submission from doing hard submission, ajax request is enough