* Modify data download function, and support unittests of inference APIs on windows, test=develop

* The import error compatible with py2 and py3, and fix unittests problems of inference APIs on Windows, test=develop

* add local data preprocess support for imagenet
test=develop

* add local data2bin tests
test=develop

* locally two tests passed
test=develop

* change according to reviews
test=develop

* add local user data conversion into full_pascalvoc_test_preprocess.py
test=develop

* change PADDLE_ENFORCE to PADDLE_ENFORCE_GE
test=develop

* change according to reviews
test=develop

* add pascalvoc preprocess script and mobilenet-ssd analyzer_tester, wait 17737

* change converting local dataset to downloading and converting tarfile
test=develop

* change the test data_path
test=develop

* change copyright (c) 2016 to copyright (c) 2019
test=develop