Added tag 2.1.5 for changeset 474b01a6d978
Fixed files missing from the source distribution
Added tag 2.1.6 for changeset b7b2c0c45e14
Added the set_exception_info() and exception_info() methods to Future which provide the missing  traceback information on Python 2.x
Added tag 2.2.0 for changeset 3540bcd722c4