[TASK] refactor LatestVersionsHelper

Fetching the latest versions from the sourceforge RSS feed its kind of unstaple.
Also it had some issues with rc and beta versions. However, there is a JSON feed
which contains all releases. This is much easier to parse.
[FIX] Fix LatestVersion JSON feed url
[FIX] suppress cli output in scheduler

When running the testrunner from the scheduler, no output on cli should be
printed. Solves: http://forge.typo3.org/issues/36593
[FEATURE] Allow absolute URIs in HTTPTest

Solves http://forge.typo3.org/issues/35850
[FEATURE] refactor registerCaretakerTestService

When installing/loading the EXT:caretaker_instance before the EXT:caretaker, 
the test services provided by the EXT:caretaker_instance were not available.
With this change, the loading order of these both extensions doesn't matter
any more.
Solves: http://forge.typo3.org/issues/13169
[TASK] Check OpenSSL key generation in UPDATE
[TASK] Raise version numbers

... to avoid confusion with the older version in TER
Merge pull request #6 from etobi/master

Awesome oversight on my side. ;) Sorry!