Add an --ignore-plugins option to calibre.exe

src/calibre/gui2/main.py

@@ -34,6 +34,9 @@ path_to_ebook to the database.
                       help=_('Log debugging information to console'))
     parser.add_option('--no-update-check', default=False, action='store_true',
             help=_('Do not check for updates'))
+    parser.add_option('--ignore-plugins', default=False, action='store_true',
+            help=_('Ignore custom plugins, useful if you installed a plugin'
+                ' that is preventing calibre from starting'))
     return parser
 
 def init_qt(args):

src/calibre/gui2/ui.py

@@ -103,6 +103,8 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, EmailMixin, # {{{
         self.gui_debug = gui_debug
         acmap = OrderedDict()
         for action in interface_actions():
+            if opts.ignore_plugins and action.plugin_path is not None:
+                continue
             try:
                 ac = action.load_actual_plugin(self)
             except: