Implement a hook to be able to influence the concatenated
and compressed resource files before they get wrapped in tags.

Resolves: #33234
Releases: 4.6, 4.7

Change-Id: I0f1a1337ab5b3fbe50692c7f342ecaccc282d052
Reviewed-on: http://review.typo3.org/7822
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter