[TASK] travi-ci: Disable hhvm functionals, linter, xlf tests

travis builds with hhvm take 20 times the time as PHP.
Since functionals are fully failing at the moment and unit tests
should be fixed first, functional tests as well as linting and
language checks are disabled on hhvm in travis for now.

Change-Id: I240a51ac098df1e2e1bcad0b6fb7dd949b8e6685
Releases: master
Reviewed-on: http://review.typo3.org/34961
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>