* add log iter argument

* ppdet log time smooth

* ppdet log eta

* fix resnet for resnet34

* fix ResNet18 and ResNet34

* update modelzoo and fix configs

* fix configs

* fix resnet bn

* check gpu for ppdet/yolov3

* add random shape descp in MODEL_ZOO

* refine doc

* not use core

* Rename object_detection to PaddleDetection
* Small fix for doc

* Add GC in train.py by defalut and change data co dataset in configs
* Update docs/INSTALL.md
* Enable build_strategy.enable_inplace = True

* Fix missing `absolute_import`

* Fix cycle import

* Fix missing export

* Remove some extra blank line and whitespaces

* Rename `create_feeds` -> `create_feed`

* Fix minor issues in tool scripts

* Add ipython notebook demo

* Tweak visualization bbox label style

* Tweak command line scripts

enable fine grained control of command flags parsing
switch to attribute style of accessing config options

* Break down visualization function

decouple it from IO operations

* Move flag parsing out of `main()`

* Fix a bug where `None` is returned instead of `{}`

* Rename `save_xxx` to `output_xxx` in command line flags

could be confusing since checkpoint is stored in `save_dir`

* Support image file extensions in upper case

* Fix type for faster_rcnn_50_2x.
* Make sure that type of cpu_num is int.

* Fix dtype for Yolov3.
* Clean unit testing.
* Add eval() for COCO-based algo.

* Unified object detection framework based on PaddlePaddle.
* Include algo: Faster, Mask, FPN, Cascade, RetinaNet, Yolo v3, SSD.