ladder 7.x-1.0-alpha4

This release contains considerable changes from the previous alpha. A few of these changes were already live on DrupalLadder.org, but many were done to move the Ladder content type (formerly Curriculum) into this module and allow for ladders to be broken into sections. See #1822922: Create new ladder content type to replace curriculum

Changes since 7.x-1.0-alpha3:

• Added function to find what ladder(s) a lesson belongs to (Issue #1822922, will be used for #1772560)
• Show empty message if there are no lessons (Issue #1822922)
• Hide the Overview label (Issue #1822922)
• Check some values to prevent undefined index notices
• Hardened the update function to make sure the field_collection module is enabled and revert the Ladder feature to ensure that the fields are created (Issue #1822922)
• Added some isset() checks to eliminate undefined index notices
• Removed unused debug statement
• Changed markup so that ladder rung lines are centered on text (Issue #1822922)
• Fixed field order, and cleaned up ladder display (Issue #1822922)
• Added field formatter to display field collection as a ladder and adjusted the output HTML (Issue #1822922)
• Removed no-longer-used lessons_curriculum (Issue #1822922)
• Switched the curriculum-to-ladder node conversion to hook_update_N() since it will only need to update existing sites (Issue #1822922)
• Added new ladder content type and fields
• Added hook_install() implementation to convert curriculum nodes to new ladder node type
• #1494972: Rename curriculums to ladders across the board
• #1792804: Fatal error when lessons_provisional is not enabled
• Fixed old Learn Drupal label
• #1487568 by Darko: fixed pass-by-reference error
• Some more work to allow Maintainers to flag lessons within a curriculum as provisional. This commit has been split somewhat arbitrarily to divide credit between g.oechsler and Alan Evans and extra caution should be taken if a revert is needed.
• Initial work to allow Maintainers to flag lessons within a curriculum as provisional. This commit has been split somewhat arbitrarily to divide credit between g.oechsler and Alan Evans and extra caution should be taken if a revert is needed.