delete.php: it seems that assign an array element to a string variable does not convert the string to an array. CR thought this was the case in the past (maybe a change in PHP7.2)

delete.php: process json answer of qfq-delete()
Dirty.php: More specific error message. In case of locking problem during form delete - return json and not an exception.
QuickFormDirty.php: Code cleanup. Interpret answer of dirty->checkDirtyAndRelease

Report.php, Constants.php: introduce constants for report column keywords. Remove code to handle unecessary 'p:' tag for delete links.

delete.php, Delete.php: reformat
Link.php: typo

delete.php: extended to support returning JSON, HTML redirect (Location) or HTML error messages.
Report.php: new adjustDeleteParameter()
Delete.php: new.
QuickFormQuery.php: delete() extended to support returning JSON and HTML

save.php: moved constants to Constants.php to reuse them in delete.php. Fixed bug by building error messages.
Sip: extended queryStringToSip() by optional Parameter $scriptName.
AbstractBuilForm: renamed formEditLink() to createFormEditUrl(). Changed createFormEditUrl() to only return the final URL, without HTML tags. Implemented createDeleteUrl().
BuildFormBootstrap, BuildFormTable: rewrote code for using createFormEditLink(). Use of createDeleteUrl().
Constants: defined SIP_TABLE, API_*
QuickFormQuery: reformat Code