* added small part with tips for IntelliJ settings

* Update CONTRIBUTING.md
Co-authored-by: NDaniel Beck <1831569+daniel-beck@users.noreply.github.com>

* Apply suggestions from code review
Co-authored-by: NOleg Nenashev <o.v.nenashev@gmail.com>
Co-authored-by: NDaniel Beck <1831569+daniel-beck@users.noreply.github.com>
Co-authored-by: NOleg Nenashev <o.v.nenashev@gmail.com>

Add system property to override inbound TCP agent address

[JENKINS-64423, JENKINS-46618] Resolve all core caused startup Illegal reflective access warnings (#5110)
Co-authored-by: NJesse Glick <jglick@cloudbees.com>

Co-authored-by: NJesse Glick <jglick@cloudbees.com>

[JENKINS-64439] "positive-number" field validator accepts non valid java numbers

Replaced deprecated IOUtils.LINE_SEPARATOR with System.lineSeparator()

Minor spotbugs issues

[JENKINS-58101] Cache blockage reasons when considering parked executors

Code cleanup

Prevent user to input 'e' or 'E'.
Except 'positive-number', I also add the restriction to 'non-negative-number' and 'number'

Bumps [jnr-posix](https://github.com/jnr/jnr-posix) from 3.0.45 to 3.1.4.
- [Release notes](https://github.com/jnr/jnr-posix/releases)
- [Commits](https://github.com/jnr/jnr-posix/compare/jnr-posix-3.0.45...jnr-posix-3.1.4)
Signed-off-by: Ndependabot[bot] <support@github.com>
Co-authored-by: Ndependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [jna](https://github.com/java-native-access/jna) from 5.3.1 to 5.6.0.
- [Release notes](https://github.com/java-native-access/jna/releases)
- [Changelog](https://github.com/java-native-access/jna/blob/master/CHANGES.md)
- [Commits](https://github.com/java-native-access/jna/compare/5.3.1...5.6.0)
Signed-off-by: Ndependabot[bot] <support@github.com>
Co-authored-by: Ndependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Fix broken 'download Maven here' link