Data dictionary made local to DataLoader

Managing data through accessors resulted being too complex. Now the DataLoader
thread contains the collected data protected by a mutex, which is unlocked at
end of parsing.
Implemented the region selection and item display

Now the user is able to visualize details on requested and offered items by
selecting the region in the related view.
The cargo capacity is now saved between sessions

Also, modified the Config interface, so the get() and set() methods can be
called directly as module-level functions.

In Trade section the text in LineEdits is aligned to right now.