python-modernize code

called with:
python-modernize --future-unicode --compat-unicode --write --nobackups -j4 mapproxy --no-six
first compat module
fix urlparse imports
fix long
fix basestring
fix StringIO
fix status check in response
fix thread import in thread local module
handle reraise_exception
fix itertools imports
fix iteritems
fix iter_encode in response
fix itervalues and iterkeys
fix proj init calls
add mocker library
adopt mocker for python 3
fix http/urllib imports for test helper
fix imports in aync  module
fix python 3 compat for tempita
use internal mocker