Enable connecting to a custom MusicBrainz server

Under the new [musicbrainz] section in the config,
you can set a server to connect to.

Closes #172.

whipper/common/config.py

@@ -21,9 +21,11 @@
 import ConfigParser
 import codecs
 import os.path
+import re
 import shutil
 import tempfile
 import urllib
+from urlparse import urlparse
 
 from whipper.common import directory
 
@@ -72,6 +74,13 @@ class Config:
     def getboolean(self, section, option):
         return self._getter('boolean', section, option)
 
+    # musicbrainz section
+
+    def get_musicbrainz_server(self):
+        server = self.get('musicbrainz', 'server') or 'musicbrainz.org'
+        server_url = server if re.match(r'^\D*//', server) else '//' + server
+        return urlparse(server_url).netloc
+
     # drive sections
 
     def setReadOffset(self, vendor, model, release, offset):