better RexTFV status
RexTFV status now visible in workspace
added doc
better error icon position
Merge pull request #850 from t-gerhard/rextfv_status

better RexTFV status
fixed a severe keyerror
fixed a wrong function call that resulted in errors not being restored by the backend when receiving RPC responses from hostmanager
Exceptions in dumpError are now caught.
Merge branch 'webfrontend_errorhandler' into errordump_fixes2