inline_entity_form 7.x-1.5

Fixes 1.4 regressions and other bugs.

Changes since 7.x-1.4:

• #2074127: Prevent error when the IEF table is trying to show a field not found on the entity.
• Clean up inline_entity_form_form_alter(), fix issues with some forms being submitted twice.
• #2174995: commerce_product_line_item_populate() not called for product line item types.
• Improve inline_entity_form_field_widget_properties_alter(), avoid calling module_exists() for non-IEF widgets.
• #2173539 by fearlsgroove: Views Bulk Operation (VBO) modify entity values broken again.
• #2170965 by jgullstr, bojanz: Prevent WSOD when Views is not enabled.
• #2165113 by andyg5000: Undefined index: #submit at inline_entity_form_form_alter().
• #2166175 by andyg5000: Don't set field values when $values is null