Summary: Create separate version file for dragonwell. Integrate dragonwell information into makefile.

Test Plan: Sanity test by make.sh

Reviewed-by: luchsh

Issue: https://github.com/alibaba/dragonwell8/issues/25

Summary:
- Added .github/commit_message_template file
- Developers are expected to use following command to create any new Git commits
`git commit -t .github/commit_message_template`

Test Plan: only review needed

Reviewed-by: kuaiwei, sanhong

Issue: #18

Test Plan: sanity test

Reviewers: 麦庶, 在弦

Reviewed By: 麦庶, 在弦

Subscribers: 三红

Differential Revision: https://aone.alibaba-inc.com/code/D857546

Summary: Updated README

Reviewers: 三红

Reviewed By: 三红

Differential Revision: https://aone.alibaba-inc.com/code/D856392

Reviewers: 三红, 梁希, 芳玺, 麦庶

Reviewed By: 三红, 梁希, 芳玺, 麦庶

Differential Revision: https://aone.alibaba-inc.com/code/D854033

Summary: Update Dragonwell version to 8.0-preview

Test Plan: built-in sanity test

Reviewers: 麦庶

Reviewed By: 麦庶

Differential Revision: https://aone.alibaba-inc.com/code/D853999

Summary:
a tool script to get sub module source
ref T19246722

Reviewers: 传胜

Reviewed By: 传胜

Subscribers: 麦庶

Differential Revision: https://aone.alibaba-inc.com/code/D850205

Summary:
  rebase jdk8u202

Test Plan:
  sanity check in make.sh

Reviewers: 传胜

Subscribers: 麦庶

Differential Revision: https://aone.alibaba-inc.com/code/D845350

Summary:
    - add make.sh
    - change HotspotWrapper.gmk to ignore file start with '.'

    Test Plan: build dragonwell on ci jenkins

    Reviewers: 传胜, 三红

    Reviewed By: 传胜, 三红

    Subscribers: 麦庶

    Differential Revision: https://aone.alibaba-inc.com/code/D794881

Reviewed-by: erikj, dholmes

Reviewed-by: erikj, martin, tbell, aph

Summary: 8036003 adds STRIP_POLICY=no_strip conditionals in some areas, but not for ZIP_DEBUGINFO_FILES blocks
Reviewed-by: erikj

Reviewed-by: shade

Reviewed-by: serb, erikj