metrics for pre-trained FPN RCNN (dmlc#693)

* number of gpus

* syncbn

* pylint

* resnetv1c

* merge

* indent

* unitest

* trigger

* norm args

* indent

* resnet v1d +0.5%

* style

* update docs

* fix args

* trigger build

* add test

* resolve conflict

* Add FPN model

* Add FPN train scripts

* Fix FPN error, Stay tuned

Training on VOC is still going on, I will report the result and log later.

* Revert "Sync from dmlc/master"

* Revert "Revert "Sync from dmlc/master""

* Update gluoncv/model_zoo/fpn/fpn.py

* Fix `FPN` Bugs

mAP on VOC07 is 58%, stay tuned.

* add faster_rcnn_fpn_resnet50_v1b model

* Update gluoncv/model_zoo/fpn/fpn.py

* Update gluoncv/model_zoo/fpn/fpn.py

* Create Readme.md

* Update Readme.md

* Update Readme.md

* Update Readme.md

* Update Readme.md

* Update Readme.md

* Rename Readme.md to README.md

* Update Train and Eval script, Support Eval VOC12 Test.

* Update scripts/detection/fpn/eval_fpn_voc12.py

* Update scripts/detection/fpn/eval_fpn_voc12.py

* Update README.md

* Update README.md

* Update fpn.py

* Update gluoncv/model_zoo/model_zoo.py

* Update gluoncv/model_zoo/model_zoo.py

* default not to use static alloc to save memory, speed is not significantly impacted.
added dilated faster_rcnn_resnet50_v1b
added mask_rcnn_resnet101_v1b

* fix missing args

* small fix

* docs

* rm unneeded file

* rm debug log

* Faster RCNN with FPN

* rm unnecessary files

pylint

rm Non-ASCII

fix syntax

lint

rm from .fpn import *

stride => strides

rm syncbn in rpn

rm syncbn arg

mask rcnn arg fix

missing "s"

* rm 's' in anchor_generators

* old model compatibility

fix

* not using RPNHead to keep backward compatibility with old models

* _strides

* mask rcnn compatibility

* docs

* rm dilated faster rcnn

* mask rcnn w/ fpn

* rm undefined functions

* change default roi mode to 'align'

* trigger build

* change name of the fpn networks

* model store update

* Fix typo (dmlc#622)

* Improve custo coco compatible detection dataset (dmlc#624)

* coco det improve for custom datasets

* allow flexible image path parser

* fix pycocotools _isArrayLike

* better comment

* clean

* Add assertions for invalid class names for VOCDetection (dmlc#614)

* Add assertions for invalid class names

* Add assertions for invalid class names (revision1)

* Add assertions/warnings for invalid class names (revision2)

* Add assertions/warnings for invalid class names (revision3)

* Add assertions/warnings for invalid class names (revision4)

* add detection paper (dmlc#628)

* add bibtex

* rephrase

* update bibtex

* Update PSP Params (dmlc#629)

* update psp params

* update with pin-device_id (dmlc#630)

* sync bn faster rcnn

* pylint

* change roi from 7 to 14, since the last fpn model we trained use 14

* add pretrained faster rcnn fpn bn

* Update model_zoo.py

* Update model_zoo.py

* fpn RCNN docs

force mxnet>=1.3.0, replace load_params with load_parameters (dmlc#398)

* force mxnet>=1.3.0, replace load_params with load_parameters

* fix pylint

Add static alloc and fix load/save_params (dmlc#183)

* fix save_params

* add warmup lr

* add static alloc

* tune coco settings

* fix load_params

* add logging to saving parameters

* tune coco param num_sample, test_post_nms

* fix params doc

* add coco settings to eval

* change coco to 2x lr schedule

* fix load_params in eval, pretrained backbone is still unchanged

update url and test oom (dmlc#79)

* rename param suggested by Tong

* pylint

* update url