- [RPC] fixed function to get the IRI loaded before the latest one;
- [GUI] refactored some code about main window's callbacks;
- [GUI] highlighted TOC entries when the mouse pointer is over the widget.
when follownig a redirect both the original (the redirect) and the
actual URI was saved in the history. So if an user, after followed a
redirect, tried to go back would reach the same redirect, this generated
a loop.