[Apache] check for license conflicts

[javeme]

Feature Description (功能描述)

Need to check dependency with licenses as follows (refer to the TODO in #1644):

• GPL
• LGPL
• AGPL

how-to:

config `license-maven-plugin` in pom.xml
execute `mvn license:aggregate-add-third-party`

http://blog.itpub.net/69918724/viewspace-2655816 https://github.com/apache/servicecomb-pack/blob/master/pom.xml#L640

possible conflicts include libs like mysql-connector and word.

[javeme]

• hugegraph-server THIRD-PARTY libs License list
• hugegraph-computer [THIRD-PARTY libs License list]

[javeme]

hugegraph-server:

1. truelicense (AGPL): hugegraph-common (fixed by #1700)
2. word (GPL): hugegraph-core (fixed by #1998)
3. mysql-connector (GPL): hugegraph-mysql/mysql:mysql-connector-java
4. jnr-posix (LGPL+GPL): cassandra-driver-core (fixed by #1822)
5. jboss-logging (LGPL): cassandra-all (fixed by #1822)

hugegraph-computer:

1. truelicense (AGPL): hugegraph-common (fixed by hugegraph/hugegraph-common#86)
2. checker-qual (GPL): hugegraph-computer (fixed by hugegraph/hugegraph-computer#149)

hugegraph-loader:

1. mysql-connector (GPL): load-from-jdbc/mysql:mysql-connector-java
2. oracle-connector (FUTC license--not sure restricted): load-from-jdbc/com.oracle:ojdbc8

hugegraph-tools:

1. None

hugegraph-hubble:

1. mysql-connector (GPL): hugegraph-loader

NOTE: the MySQL connector dependency is optional, can let users to download by themselves: https://www.apache.org/legal/resolved.html#optional

[z7658329]

• hugegraph-loader: THIRD-PARTY.txt
• hugegraph-tools: THIRD-PARTY.txt
• hugegraph-hubble: THIRD-PARTY.txt

[imbajin]

Reopen this issue because of the VOTE mail:

Mark this issue as the 1st priority to fix, TODOs:

• [x] find the GPL usage
• [x] find the CC-BY usage
• [x] use a action/ci to check them automatically
• [x] fix the License Header problem (list the file)
  • [x] StringEncoding*
  • [x] SnowFlake*
  • [x] TinkerPop*

Ways to find possible 3rd import:

• search author in all files
• search Copyright in case-sensitive mode in *.java and other source code files
• search refer in non-case-sensitive mode
• search Reference in word-match mode (in source code files)

Some other refer:

1. Apache Release License README - Wiki