[entropy.i18n] try recover from invalid filesystem encoding

This should also help with invalid UTF-8 characters returned by _()
[Rigo] fix Application View rendering when window is maximized
[entropy.db] drop deprecated methods closeDB() and commitChanges()
[Rigo] make possible to disable the updates notification box
[todo] update TODO
[Rigo] fixup Application View rendering when window is maximized
[Rigo] add support for accelerators

From the main Rigo window, these are the currently supported accelerators:
- CTRL+A: move the focus to the search bar, put the cursor at the beginning
- CTRL+B: move the focus to the search bar, send a backspace character to it
- CTRL+F: move the focus to the search bar
- CTRL+K: move the focus to the search bar, kill the right-most text
- CTRL+M: load the preferences Menu
- CTRL+P: move the focus to the Application View widget
[Rigo] make Glade-3 happy and acknowledge its xml changes once and for all
[Rigo] update rigo.pot
[todo] update TODO
[entropy.client] drop deprecated methods
[entropy.tools] drop get_random_temp_file, deprecated
[entropy.client] drop get_file_permissions, deprecated
[entropy.fetchers] drop UrlFetcher.output, deprecated in 2010