refs #15778. replace spaces by tabs + removed some spaces/tabs. Thanks Helena Halperin (IBM, CCLA). !strict.
refs #16717. add a fill parameter to TabBar. If set to "auto" (default value), behave as in 1.8. If set to "always", resize its children so that they evenly fill the entire bar space. If set to "never", do not resize the children. Thanks Sebastien Brunot (IBM CCLA).