compilers.
With the current setup, OpenBSD 6.0's g++4 on a VM with 4GB ram can't even
build Mumble, because the generated .cpp file from mumble_flags.qrc is
32MB.
This commit attempts to work around that by splitting our SVG flags into
separate resource files.
To make it easier to work with from the qmake build, we now also generate
a mumble_flags.pri file that will automatically add all necessary .qrc
files to RESOURCES.
