[TASK] Cleanup felogin

Change-Id: I9ceeb1e7c142a3daaf20886f94c8a1d3295df99a
Resolves: #45123
Releases: 6.1
Reviewed-on: https://review.typo3.org/17995
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
[TASK] Cleanup css_styled_content

Change-Id: Id229452ab6eac65d028555c5b42300be25da7e1a
Resolves: #45115
Releases: 6.1
Reviewed-on: https://review.typo3.org/17984
Reviewed-by: Philipp Gampe
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
[TASK] Cleanup feedit

Change-Id: I8eca6524c69ee71973411b4b791ee7b33bdcda82
Resolves: #45116
Releases: 6.1
Reviewed-on: https://review.typo3.org/17985
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn