[TASK] Comment legacy files to be removed with 6.2

[TASK] Comment legacy files to be removed with 6.2

The 'old' class files before namespace switch are commented
to be removed with TYPO3 7.0, but they should be scheduled
for removal with 6.2.

Change-Id: Ib74816834d4046873f6d31b4e3aac3094d0f5289
Resolves: #43120
Releases: 6.0
Reviewed-on: http://review.typo3.org/16585
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn