Make sure that other installed plugins don't affect the same keyword argument.

def setup(self, app):
        '''
        Make sure that other installed plugins don't affect the same keyword argument.
        '''
        for other in app.plugins:
            if not isinstance(other, MySQLPlugin):
                continue
            if other.keyword == self.keyword:
                raise PluginError("Found another mysql plugin with conflicting settings (non-unique keyword).")
            elif other.name == self.name:
                self.name += '_%s' % self.keyword