[gedit-list] Fix Bug 342918 and even support universal encoding detection

[Ma Xiaojun <damage3025 gmail com>]

https://live.gnome.org/Gedit/RoadMap
One of the item is "Changing encoding of opened files", I'm going to work on it.
Can any previous developer explain is there any known difficult?
Why making encoding of a document read-only?

Changing encoding would only be a workaround.
Universal encoding detection is right way to go.
As our friend editor has done this for more than 2 years now.
http://kate-editor.org/2010/08/26/encoding-detection-revised/

We don't have KEncodingProber.
But I found a library to handle encoding detection stuff.
http://code.google.com/p/uchardet/
Can I use it directly or I need to port a GNOMEism library?