It only does it once, when saving it (at exit).

This way we only have one representation of the history in memory
instead of 2, and we don't need a ConfigTree for this, standard streams are
sufficient.

We were inserting elements into the toolbar at invalid positions.
Now the indices have been corrected and an assertion added to make
this sort of error more obvious in the future.

Clients still need to be updated.

[ #7876 ] Remove unused class attribute, rename all attribute use use m_ for private member, m_p for private pointer, m_s for private static and m_sp for private static pointer

[ #7876 ] Update copyright from 2010 to 2012 (next version wont be released until then, so why not doing it now)