This fixes a bug that presents when running 'make distcheck' from a clean builddir.
The rcc tool is quirky and only honors files in the same directory as the qrc. When doing an out-of-tree build (as 'make distcheck' does), the generated translation files end up in a different path, so rcc can't find them.
Split them up so that rcc is run twice: once for static source files and once for generated files.