[BUGFIX] Improve jumpUrl download of large files

* Prevent output-buffering
* Add Content-Length header

Fixes: #41718
Releases: 6.2, 6.1, 6.0
Change-Id: I8a1a33dc4337a5947bafbad980b73343be637da7
Reviewed-on: https://review.typo3.org/15508
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter
[BUGFIX] Skip APC test on php 5.3

travis suddenly shows a failed APC test on PHP 5.3. We have had issue
with the stability of APC tests before, there are some race
conditions in APC. For now we just skip the failing test on PHP 5.3

Resolves: #49682
Releases: 6.2

Change-Id: If52b3a823589d6dc83b52323b8ae57a0227571c9
Reviewed-on: https://review.typo3.org/21913
Reviewed-by: Steffen Ritter
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters