Sorted out mime initialization.

Every mime related function in main __init__.py has a flag check for the
check if initialization has already done. This is nonsense, since it
should be done implicitly early on the converter is starting.

This commit straight the things out, and initialization is done in cli
module.

Also, function guess_type was removed, since it's just a proxy for
mimetypes.guess_type function.

ebook_converter/ebooks/conversion/plugins/html_input.py

@@ -1,23 +1,19 @@
 import functools
+import mimetypes
 import os
 import re
 import tempfile
 import urllib.parse
 
 from ebook_converter.constants_old import islinux, isbsd
-from ebook_converter.customize.conversion import (InputFormatPlugin,
-        OptionRecommendation)
+from ebook_converter.customize.conversion import InputFormatPlugin
+from ebook_converter.customize.conversion import OptionRecommendation
 from ebook_converter.utils.localization import get_lang
 from ebook_converter.utils.filenames import ascii_filename
 from ebook_converter.utils.imghdr import what
 from ebook_converter.polyglot.builtins import as_unicode
 
 
-__license__ = 'GPL v3'
-__copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
 def sanitize_file_name(x):
     ans = re.sub(r'\s+', ' ', re.sub(r'[?&=;#]', '_', ascii_filename(x))).strip().rstrip('.')
     ans, ext = ans.rpartition('.')[::2]
@@ -99,7 +95,6 @@ class HTMLInput(InputFormatPlugin):
         from ebook_converter.ebooks.oeb.base import (DirContainer,
             rewrite_links, urlnormalize, BINARY_MIME, OEB_STYLES,
             xpath, urlquote)
-        from ebook_converter import guess_type
         from ebook_converter.ebooks.oeb.transforms.metadata import \
             meta_info_to_oeb_metadata
         from ebook_converter.ebooks.html.input import get_filelist
@@ -164,7 +159,7 @@ class HTMLInput(InputFormatPlugin):
             self.added_resources[path] = href
         self.urlnormalize, self.DirContainer = urlnormalize, DirContainer
         self.urldefrag = urllib.parse.urldefrag
-        self.guess_type, self.BINARY_MIME = guess_type, BINARY_MIME
+        self.BINARY_MIME = BINARY_MIME
 
         self.log('Rewriting HTML links')
         for f in filelist:
@@ -262,7 +257,7 @@ class HTMLInput(InputFormatPlugin):
         if link not in self.added_resources:
             bhref = os.path.basename(link)
             id, href = self.oeb.manifest.generate(id='added', href=sanitize_file_name(bhref))
-            guessed = self.guess_type(href)[0]
+            guessed = mimetypes.guess_type(href)[0]
             media_type = guessed or self.BINARY_MIME
             if media_type == 'text/plain':
                 self.log.warn('Ignoring link to text file %r'%link_)
@@ -275,7 +270,7 @@ class HTMLInput(InputFormatPlugin):
                     pass
                 else:
                     if img:
-                        media_type = self.guess_type('dummy.'+img)[0] or self.BINARY_MIME
+                        media_type = mimetypes.guess_type('dummy.'+img)[0] or self.BINARY_MIME
 
             self.oeb.log.debug('Added', link)
             self.oeb.container = self.DirContainer(os.path.dirname(link),