- add `inceptionYear` element, and use it in `copyright bottom`
- add missing version declaration for `maven-gpg-plugin`
  more stable build and fix related warning message
- add `maven-enforcer-plugin`
  more straightforward error message when `maven`/`java` version is not satisfied

- reorder pom elements
  - sort `GAV` elements together
  - bring user concerned info(e.g. licenses) forward
  - bring dev concerned basic info(e.g. dependencies) before profiles
- use `https` instead of `http` for URLs
- change whitespace tabs to spaces for consistency

This project need JDK 11 to compile, but target to JDK 8.

IDEA need uncheck "use --release" in Preferences |
Build, Execution, Deployment | Compiler | Java Compiler
, to build success.

fix #470

https://github.com/jboss-javassist/javassist/issues/471

Correct maven-compiler-plugin JDK version for IDEA import Compiler bytecode version.

Remove JvstTestRoot's constructor, otherwise IDEA cannot show Run icon aside testMethod.
Another way is adding suite() static method to those classes.

Now we can clone and open project with IDEA 2023.2. Debug single test case with IDEA is very useful.

pom.xml changes:
- lower compile source/target to 1.7 (from 1.8, introduced with Javassist 3.24.0)

There were minimal changes:
Some tests had their own runners these were discontinued as IDEs/maven run the tests anyway.
Removed the main methods for these.
2 tests were dependent on the running order so added the test sorter.

All tests succeed on junit 4 with legacy support.

In order to squash the mvn build warnings.

In order to squash the mvn build warnings.

Move the test output folder 'runtests' to target or build directory so that mvn clean can clean that.

The following warning when invoking `mvn versions:display-plugin-updates` does not appear anymore:
```
[WARNING] Some problems were encountered while building the effective model for org.javassist:javassist:bundle:3.19.0-GA
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin is missing. @ line 137, column 15
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-jar-plugin is missing. @ line 160, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
```

To get the test case JvstTest4.testMethodParameters() to work
the <testSource> and <testTarget> elements are set to "1.8"
and the compiler argument "-parameters" is added.