Fixes https://github.com/owncloud/core/issues/10366

in order to prevent false-positives on the code checker - exec and eval will not longer be grepped for

ref #10392

ref #10392

Properly initialize $apps array

Determining the file size using the exec() method is implemented for Linux, BSD, and Windows. However, on systems matching neither platform name (like SunOS), the fall-through path will return a file size result constituting a zero size instead of an invalid null return value.

* instanceof \OC\Files\View
* fix misplaced paranthesis
* remove misplaced character in comment

Fix #9972

Fix #9972

Previous commit was not based on master, retry. Removed broken tar cutter, double extensions are not possible in temp files. Added tar support. Fixed extension switch.