Item12839: Implement default REST security changes

Defines new InsecureREST setting in Foswiki.spec.   TEMPORARILY ENABLED.
This will be disabled prior to Foswiki 1.2

Add warning log records, with referer, to the REST security rejections,
so that admins can figure out which pages are making incorrect rest
requests.

Disable core checks for WysiwygPlugin - These should be enforcing their
own requirements.

Update release notes

Fix unit tests to disable rest default security checking.  Each test
enables settings as needed.

git-svn-id: http://svn.foswiki.org/trunk/core@17592 0b4bb1d4-4e5a-0410-9cc4-b2b747904278