What is the purpose of the change

Update pom for into apache incubator, partial fix for this issue: https://issues.apache.org/jira/projects/DUBBO/issues/DUBBO-7?filter=allopenissues

Brief changelog

1. update pom.xml license
2. update scm, mailLists, issueManagement, organization
3. add DISCLAIMER

Verifying this change

All unit tests are pass

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