Consistently let SetDesingMode functions take bool argument

...to avoid "warning C4805: '!=' : unsafe mix of type 'bool' and type 'sal_Bool'
in opertaion" style errors.  Additionally, mark those functions that are virtual
overrides as such.

Change-Id: I64f919f7e2d8f6224303f9bac67f6270d58de014
warning C4805: '!=' : unsafe mix of type 'sal_Bool' and type 'bool'

Change-Id: I3d4f1ac0debf506e3c4f1ce9143cb8c1cf66925d