git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/tags/v1_2_17@1333769 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/tags/v1_2_17_rc3@1334596 13f79535-47bb-0310-9956-ffa450edef68

git-svn-id: https://svn.apache.org/repos/asf/logging/log4j/tags/v1_2_17@1342873 13f79535-47bb-0310-9956-ffa450edef68

The new build requires JDK8 or later, and a JDK6 installed as a maven
toolchain.

Main changes include:
* switch to Maven 3, requiring JDK7 to invoke
* switch to latest (compatible) maven plugins, requiring JDK8 to invoke
* introduce two profiles: toolchain (default) and no-toolchain
  * toolchain profile uses maven toolchains feature with JDK6
    (can also use JDK7) and source/target version of 1.4,
    for compatibility with JDK 1.4/5/6/7 and beyond
  * no-toolchain profile uses default system JDK with
    source/target version of 7,
    for compatibility with JDK 8/9/10/11/17 and beyond
* stop building NTEventLogAppender.dll from maven by invoking ant
  (instead use the checked-in version)
* replace some plugin use with resources section
* replace some ant tasks with maven clean plugin
* change all project metadata for correctness
* remove duplicate LICENSE and NOTICE files and use the main ones
* set default encoding to UTF-8 to silence some warnings
* enable running all unit tests instead of a whitelist
* change when and how site is generated
* customize site templating for modern site plugin
* remove unused and unsupported ant build files
* update INSTALL document to match changes

Sets up a matrix build using github actions that runs on every push.
The following combinations all work:

* Toolchain 1.6, JDK 11, OS ubuntu-18.04
* Toolchain 1.6, JDK 11, OS ubuntu-20.04
* Toolchain 1.6, JDK 11, OS windows-2019
* Toolchain 1.6, JDK 11, OS windows-2022
* Toolchain 1.7, JDK 11, OS ubuntu-18.04
* JDK 8, OS ubuntu-18.04
* JDK 11, OS ubuntu-18.04
* JDK 17, OS ubuntu-18.04
* JDK 8, OS ubuntu-20.04
* JDK 11, OS ubuntu-20.04
* JDK 17, OS ubuntu-20.04
* JDK 8, OS windows-2019
* JDK 11, OS windows-2019
* JDK 17, OS windows-2019
* JDK 8, OS windows-2022
* JDK 11, OS windows-2022
* JDK 17, OS windows-2022

Delete several integration-style tests that are broken.
They are not being run by the main build (because they are broken).

Now that the main build runs all tests, remove the old way of running
them with ant or bash.

MDCTestCase has some nasty reflection inside that is not allowed anymore
on JDK >= 17. Detect and trap the error.

Changes most tests to use unique output files during their runs, so that
when they run in parallel or out-of-order or interactively they do not
cause test failures, reducing flakyness of test runs.

Hand-picked changes from trunk

* Remove outdated roadmap page
* Update navigation to link to renamed mailing lists page
* Remove link to non-existent wiki

These changes are incomplete because contributors cannot test the
maven release plugin setup.

Disables:
* JMSAppender
* JMSSink
* SimpleSocketServer
* SocketHubAppender
* SocketServer
* SocketNode
* TelnetAppender

These classes now log an error instead of making network connections.

Their external APIs remain intact to allow code using them to migrate
without blowing up before runtime.

Added tests for their remaining behavior.

Adds warnings:
* for SyslogAppender unless logging to a local loopback address
* for SMTPAppender:
  * Does not warn about safe(r) use talking to the local loopback.
  * If using SMTPS, warn that host will not be verified (CVE-2020-9488).
    Note this commit does not actually fix the security issue. Instead
    it warns an upgrade is needed (or a change in configuration).
  * If using SMTP, warn about an unencrypted protocol.
* deprecation warnings on disablec classes
* deprecation for SocketAppender since it's the client side of the
  disabled server code

Disables:
* jmx.Agent

This class now throws an error instead of making network connections.

Disables:
* JDBCAppender

This class now logs an error instead of making network connections.

Disables networking in:
* ExternallyRolledFileAppender

Behavior reduces to be a normal non-rolling FileAppender.

Avoids trying to determine whether java >= 1.2 since if this version
of the code loads java >= 1.4.

Disable a set of flaky integration tests that depend on specific JDK
behavior (usually due to expecting a specific stack trace), when not
running using the toolchain JDK.