Replace browserDefault with is_default_page

[gforcada]

So we remove the last usage of browserDefault and thus can be removed from CMFPlone.

See plone/Products.CMFPlone#3737

[mister-roboto]

@gforcada thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[gforcada]

@jenkins-plone-org please run jobs

[mauritsvanrees]

I added a few commits, updating the news snippet and using aq_parent instead of __parent__. Maybe those should have been suggestions.

I also saw similar code in reviewlist.py. It was not using the skin script, but it was calling the same function from plone_utils, and handling it with the slightly confusing code that that you replaced. So I updated it here as well. The full_review_list page (linked from the review portlet) now shows like this:

BTW, the checkboxes here are useless, as no buttons are shown that would do anything with the suggestion. But that is a different issue.

@gforcada Sorry for hijacking your PR! Hope it's okay.

[mauritsvanrees]

@jenkins-plone-org please run jobs