Deprecation: #86320 - Mark internal $TSFE properties as protected
See forge#86320
Description
The following properties of class 
        \TYPO3\ have changed their visibility to be protected from public and should not be called any longer.
The properties are only used and needed internally.
- login- Allowed - In - Branch_ - mode 
- cache- Time - Out - Default 
- cache- Content - Flag 
- cache- Expires 
- is- Client - Cachable 
- no_- cache - Before - Page - Gen 
- temp- Content 
- pages- TSconfig 
- unique- Counter 
- unique- String 
- lang
Impact
Calling any of the properties will trigger a PHP 
        E_ error.
Affected Installations
Any TYPO3 installation directly accessing any of the mentioned properties.
Migration
Properties are only for internal use, no migration available.