Update QR code

update ratio_list in db config

add init to fc1

update det_r50_vd_sast_totaltext.yml

add export to limit GPU-memory-usage

update cpp_infer to 2.0

Dyg db

fix bugs in DetResizeForTest

update py inference to 2.0 and delete fluid

python to python3

add FAQ

Update det_basic_loss.py

删除重复赋值[self.main_loss_type]

set default use_gpu to False