client: implement the 'in' keyword for a client object Check if a revision number or a changeset hex matches a changeset in the client repository. The internal tries to create a ctx object. Returns False If the ctx creation fails. This patch also adds the corresponding tests.

import common
import hglib

class test_encoding(common.basetest):
    def test_basic(self):
        self.client = hglib.open(encoding='utf-8')
        self.assertEquals(self.client.encoding, 'utf-8')