Merge branch 'release/v2.5.1'
adding ids to metabox row settings
added extra param on class hook in order to prevent multiple queries
Merge pull request #186 from iamntz/class-hook

added extra param on class hook in order to prevent multiple queries
Fixed a bug that caused editing a submission to change the user_id that the submission was attached to.
Changed the method for getting user_id to  get_current_user_id();
The required field error should now be translatable.
Fixed a bug that caused Rich Textareas to wrongly encode HTML when repopulated.
checking for field list before looping through it
Add instructions for contributing

Fix #190 https://github.com/wpninjas/ninja-forms/issues/190

* Include best practices for PR branch names, commit messages, and code documentation moving forward
* Add GitHub-formatted readme, with a link to contributing instructions
Merge pull request #183 from BFTrick/metabox-row-ids

Adding IDs to Metabox Row Settings
Merge pull request #189 from BFTrick/must-have-form-fields

Checking for Field List Before Displaying it
Merge pull request #191 from naomicbush/issue/190

Add instructions for contributing
Fixed a bug that caused the "Back to submissions" button not work.
Merge branch 'develop' of https://github.com/wpninjas/ninja-forms into develop
Changed the display of the field description so that it only outputs if the "Add Description" box is checked.
Fixed a bug that caused entries of the number zero to be considered empty for required field validation purposes.
* Fix: variable name $sub['id'] should be $sub_id in admin submissions view

This error caused a PHP Notice on the admin page that lists submissions.
It was introduced with 1e39788a2ea6e21b8a3d55674924bb1731653de1
fix button close

Button close get IE 9 display error
not sending attachment parameter to wp mail when not needed