1. Disable the MySQL client and LZO library by default when building the Doris.
MySQL client library is used for MySQL external table feature.
This feature will be replaced by the new ODBC external table soon.
LZO library is used to compress/decompress data of some old data format of Doris,
which is no longer used anymore.
2. Add missing license to some files.
3. For all non-Apache-License code, all are explained in NOTICE file and the corresponding license is declared.
4. Remove the js source code from webroot, it will be downloaded as thirdparty
Currently we have implemented the plugin framework in FE.
This CL make the original audit log logic pluggable.
The following classes are mainly implemented:
1. AuditPlugin
The interface of audit plugin
2. AuditEvent
An AuditEvent contains all information about an audit event, such as a query, or a connection.
3. AuditEventProcessor
Audit event processor receive all audit events and deliver them to all installed audit plugins.
This CL implements two audit module plugins:
1. The builtin plugin `AuditLogBuilder`, which act same as the previous logic, to save the
audit log to the `fe.audit.log`
2. An optional plugin `AuditLoader`, which will periodically inserts the audit log into a Doris table
specified by the user. In this way, users can conveniently use SQL to query and analyze this
audit log table.
Some documents are added:
1. HELP docs of install/uninstall/show plugin.
2. Rename the `README.md` in `fe_plugins/` dir to `plugin-development-manual.md` and move
it to the `docs/` dir
3. `audit-plugin.md` to introduce the usage of `AuditLoader` plugin.
ISSUE： #3226
