Osdeps qwt5 osg_qt4

[pierrewillenbrockdfki]

Mark qwt5 and osg_qt4 non-existent on more platforms

[pierrewillenbrockdfki]

These are the bits that are left when i remove the uneeded stuff from https://github.com/pierrewillenbrockdfki/rock_core_package_set/tree/feature/qt4-qt5

[chhtz]

Regarding QWT, there is actually another PR #202 which suggests to install libqwt-qt5-dev instead of libqwt5-qt4-dev. I don't have any packages with a non-optional dependency on QWT, so either solution is fine for me.

[pierrewillenbrockdfki]

Regarding QWT, there is actually another PR #202 which suggests to install libqwt-qt5-dev instead of libqwt5-qt4-dev. I don't have any packages with a non-optional dependency on QWT, so either solution is fine for me.

qwt5 is not about qt5 support, it is about qwt5 support; qwt5 generally is compiled for qt4, while qwt6 generally is compiled for qt5.

libqwt-qt5-dev evidently is qwt6, it installs Qt5Qwt6.pc.

[chhtz]

qwt5 is not about qt5 support, it is about qwt5 support; qwt5 generally is compiled for qt4, while qwt6 generally is compiled for qt5.

libqwt-qt5-dev evidently is qwt6, it installs Qt5Qwt6.pc.

We could also add qwt6 or a generic qwt osdep then. (I don't have any strong opinion for either solution).