Add commands to pull translation from transifex

tx - transifex cli client should be installed in the system.
It's free software and is available in Debian archive.

Run following commands:
1. Init your authorization token
$ make transifex_init

2. Pull translations
$ make transifex_pull

                  <xsd:element name="Generic">
                    <xsd:complexType>
                      %(toolchain_makefile)s
                    </xsd:complexType>
                  </xsd:element>