[MENFORCER-430] Allow one of many files in RequireFiles rules to pass

[raupachz]

This PR resolves the issue MENFORCER-430.

Given a list of files it was not possible to enforce only a list where only one filed would be sufficient.
For example check if one of the following files exists:

• README
• README.md
• README.adoc

A new paramenter satisfyAny was added to AbstractRequiresFiles. If satisfyAny is true then it is enough if one of the files passes the check.

This PR affects the following built-in rules:

• RequireFilesDontExist
• RequireFilesExist
• RequireFilesSize

Tests have been added.

I do not know if the documentation of the builtin-rules updates itself with the new paramenter satisfyAny or if I have to do this myself.

Please note this is an up-for-grabs issue and given my lack of experience in Maven Development I might have missed something.

---

Following this checklist to help us incorporate your
contribution quickly and easily:

• Make sure there is a JIRA issue filed
  for the change (usually before you start working on it). Trivial changes like typos do not
  require a JIRA issue. Your pull request should address just this issue, without
  pulling in other changes.
• Each commit in the pull request should have a meaningful subject line and body.
• Format the pull request title like [MENFORCER-XXX] - Fixes bug in ApproximateQuantiles,
  where you replace MENFORCER-XXX with the appropriate JIRA issue. Best practice
  is to use the JIRA issue title in the pull request title and in the first line of the
  commit message.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Run mvn clean verify to make sure basic checks pass. A more thorough check will
  be performed on your pull request automatically.
• You have run the integration tests successfully (mvn -Prun-its clean verify).

If your pull request is about ~20 lines of code you don't need to sign an
Individual Contributor License Agreement if you are unsure
please ask on the developers list.

To make clear that you license your contribution under
the Apache License Version 2.0, January 2004
you have to acknowledge this by using the following check-box.

• I hereby declare this contribution to be licenced under the Apache License Version 2.0, January 2004

• In any other case, please file an Apache Individual Contributor License Agreement.

[slawekjaranowski]

@raupachz thanks for PR - looks ok.

Please add corresponding documentation in this PR - we will have complete change.
Files to edit are in https://github.com/apache/maven-enforcer/tree/master/enforcer-rules/src/site/apt

[raupachz]

@slawekjaranowski Thank you for reviewing. PR is updated.

[slawekjaranowski]

@raupachz thanks