libfreenect-dev implicit dep.

from testing on 2016-02-19 due to an transitively dependency on blender
affected by RC bug(s) 804678 and 810065.

testing (Closes: #810354)

This reverts commit 9be0cda6.

ease backporting.

* Remove unneeded versioned dependencies.
* Update Standards-Version to 3.9.4 (was 3.9.3 before).

* Revert name change libvisp -> libvisp2 but keep development package
name as libvisp-dev.
* Add missing space in dependencies.
* Remove unrequired dependency toward libopencv-highgui-dev.