Remove "experimental optimizations". These are compiler flags that are...

Remove "experimental optimizations". These are compiler flags that are selected on a per-compiler basis, but the latest detected compilers are from the gcc-4.x series. Build the frontend with the sndfile io routines, it should be able to read RAW PCM and WAV from stdin since at least 3.99.0. As per upstream request. Append "-Wl,--as-needed -Wl,-z,defs" to LDFLAGS to get rid of unnecessary dependency on libncurses.