Controlling overriding output files from dicom import

* add checkbox to gui if overriding allowed
* if not, it is checked whether the file to be written exists and the
* name is extended by smalles possible integer i _<i>
Merge branch 'bug-13303-Dicom-import-overriding-files'
COMP: removed callgrind include from composite mapper
Merge branch 'bug-14055-Callgrind2'