On using different library name when building for qt5

[Povilas K. <po...@ra...>]

Hey,

Would the maintainer be open to patches that change the name of the
library to libqwt-qt5 when building for QT5? As it stands now, the Qt4
and Qt5 versions of the library have the same name and thus it's not
possible to install them side by side.

Thank you,
Povilas