Feature - Make page callouts configurable 

since verion 6.1.0, changed again in 8.0.1

If EXT:page_callouts is installed, information is displayed in the page module, if broken links exists.

Since this has a small performance impact, is not really necessary if broken links are fixed regularly.

This is now configurable via:

• extension configuration: "Show message in page module if broken links exist on page" [showPageCalloutBrokenLinksExist] (default: "depends on user settings")
• user settings: "Show message in page module if broken links exist on page" [tx_brofix_showPageCalloutBrokenLinksExist] in tab "Broken links" (default: on), only available if extension configuration showPageCalloutBrokenLinksExist is set to "depends on user settings".

The information is only displayed if extension configuration is set to "Always" or "depends on user settings" and the user settings is active. Additionally, page_callouts mubst be installed.