Merge pull request dragonflyoss#1484 from pouchrobot/auto-doc-2020-09-20

docs: auto generate Dragonfly cli/api/contributors docs via code

Merge pull request dragonflyoss#1456 from ansinlee/master

add preheat implements

Merge pull request dragonflyoss#1429 from zhaxzhax/fix-#1428

bugfix: fix missing error message 'Unable to autodetect advertiser ip

Merge pull request dragonflyoss#1375 from lowzj/fix-ByteBuffer-gc

optimize: release allocated ByteBuffer explicitly

Merge pull request dragonflyoss#1353 from lowzj/fix-deleteTaskFiles

fix: don't delete the parent directory of the task file

backport to 1.0.x

bugfix: initialize dfget downloader in dfdaemon

Signed-off-by: lowzj <zj3142063@gmail.com>

Merge pull request dragonflyoss#1085 from Starnop/retry-report

refactor: handle errors gracefully

Merge pull request dragonflyoss#1021 from Starnop/supernode-priority

feature: add weight for node config

Merge pull request dragonflyoss#771 from Starnop/bug-ip

feature: add golbal dfget params to the dfdaemon config

Merge pull request dragonflyoss#674 from yeya24/feature/add-version

feature: add more version information to both cmd and router