Merge branch 'development' of https://github.com/Joomla-Bible-Study/Joomla-Bible-Study into development

Conflicts:
	build/packages/addons/com_jbsmigration.zip
	build/packages/addons/joomsef_com_biblestudy.zip
	build/packages/component/com_biblestudy.zip
	build/packages/modules/mod_biblestudy.zip
	build/packages/modules/mod_biblestudy_podcast.zip
	build/packages/pkg_biblestudy.zip
	build/packages/plugins/plg_biblestudy_backup.zip
	build/packages/plugins/plg_biblestudy_finder.zip
	build/packages/plugins/plg_biblestudy_podcast.zip
	build/packages/plugins/plg_biblestudy_search.zip

	Removed the function in the teacher model that checked if teacher could be removed by looking at study table. Seemed uneeded here and not present in other models.