Issue #406 - prevent user to save survey without title
Issue #405 - prevent user to go to notifications when survey not saved

* in addition, we check if questions are available before going to translations
Issue #409 - correct text tooltip permission levels
Issue #410 - correct spelling mistake

* a new issue #421 was opened because the text actually refers
to functionality that is not used at this moment.
Issue #413 - make assignment name and dates mandatory fields
Issue #415 - minor fixes in alt text
Issue #422 - survey changes lead to NOT-PUBLISHED status
* when deleting a question, deleting a survey group
and inserting a question, the survey status now
also becomes NOT_PUBLISHED. Other survey changes
already had this effect.
Issue #412 - exit preview window menu is fixed and anchored to the top

When previewing a large survey the exit button now remains visible
Issue #423 - update selectedSurvey property on changed selection
Issue #401

Survey preview number styling looks strange. Also made it consistent to
the question list bullets in the edit screen
Issue #424 - add requirements documents as markdown files to /doc
Issue #424 - add Maps file in markdown format
Issue #424 - Rename from FlowRequirements to Requeriments
Issue #425 - remove wrong selected survey change

* We set the published status to 'NON_PUBLISHED' when we change the survey
Here, I confused a deleted survey group with a deleted question group.
Issue #426 - only add published surveys to 'all survey' list
Issue #426 - better implementation of select all published surveys
Merge branch 'develop' into release/1.6.6.3
Issue #326 - fix all survey selection for bootstrap tab
Merge branch 'develop' into release/1.6.6.3
Merge branch 'release/1.6.6.3'