Add mechanical meter to contrib

update linux_build.md and CMakeLists.txt

pull before pr

* fix bug

track official

2. add the description of  deployment based on cpu

* modify pspnet cityscapes iou

* add loss check

1. Fix the bug which original height and width are in wrong order when using analysis mode to infer.
2. Add the resize step when visualizing the segment inference result.
3. Polish the document of README.md, linux_build.md and vis.md, describe more details specifically.

* Update labelme2seg.md

* Update jingling2seg.md

* update model_builder.py

* update loss_select.md

* init deepglobe_road_extraction.yaml

* update download_mini_deepglobe_road_extraction.py

* update model_builder.py

* fp16_err

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* add fp16 and multiple gpus train

* improve create_dataset_list