EDIT

ref #8248 Check for existing media and references

ref #8248, #6774 Fix order of term import

• add top level term property to import/export

ref #8248 Fix possible NPE

ref #6774 Move recursive model export to util class

ref #8248 Add character to export (partially)

ref #8248 Add feature to export (partially)

ref #8248, #6774 Add character to export

• adapt test

ref #8248, #6774 Add sources to import/export

ref #8248, #6774 Improve import/export performance

ref #8248, #6774 Add progress monitor to import/export