Convert calibre modules to ebook_converter.

Here is the first batch of modules, which are needed for converting
several formats to LRF. Some of the logic has been change, more cleanups
will follow.

ebook_converter/ebooks/mobi/langcodes.py

@@ -6,7 +6,7 @@ __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
 
 from struct import pack
-from calibre.utils.localization import lang_as_iso639_1
+from ebook_converter.utils.localization import lang_as_iso639_1
 
 lang_codes = {
         }