Previously the 'Rename Function' dialog would pop-up in the top left
corner if triggered inside the Disassembly or Decompiler view. This
commit changes the behaviour so that the Dialog will now be pop-up in
the center of the MainWindow by simply replacing the 'parent' pointer of
the QInputDialog object with that of the mainWindow (this->mainWindow)
* Show in action for global variables and functions
* Copy address of global variable or function referenced by the cursor selection
* Rename global variable
