bash_completion: support GNU sed 3 and non-GNU sed
replaced command 'Q' introduced in GNU sed 4, in order to support
platforms with older sed.
abort: repository a/.hg not found!
255
requesting all changes
abort: error: Connection refused
255
abort: repository a/.hg not found!
255
abort: destination '../a' already exists
1
abort: repository a/.hg not found!
255
abort: destination 'q' already exists