Use Qt5 for qtjsruntime

Changed minimum version:
* cmake 2.8.11
* Qt 5.1.1

Used Qt 5.1.1 because that is what I have in my OpenSUSE 13.1/Tumbleweed. So far I found no need to go for a higher version, even if I compiled 5.2.1 for CI server.

cmake 2.8.11 because that is usually recommended for Qt5 and cmake for simpler CMakeLists.txt (CI has  that as well). Cmp. e.g. https://www.kdab.com/modern-cmake-with-qt-and-boost/