* in the undo/redo list use an object's label and not the internal name
* check by the transaction ID instead of name to open a transaction to make the workbenches independent of implementation details of the core system
* when rejecting a task do not call undo() because this is not the same as aborting a pending transaction
* this also fixes the warning: <App> Document.cpp(1182): Cannot commit transaction while transacting
- people should be informed that there is a shortcut available (that was recently added)
- make the shortcut also translatable since "Del" means nothing in e.g. German
- minor code style fix in TaskDressUpParameters.h
Added a new class: TaskDlgFeatureBased which currently contains common
code for TaskDlgSketcherBasedParameters::reject() as well as the same
methode for TaskDlgDressUpParameters.
It's likely that other Feature task dialogs will inherit this class too.
