Prevents compiling those sources many times, once for each debug
program using it.

There's just one caller, i.e. ScanGenericTags(), which is documented
to throw exceptions.

This reverts commit c84bae73.  A
configuration option is not necessary, because the PcmConvert
constructor knows already whether integer or floating point is needed.

release v0.21.19

Google Play refuses uploads with a lower targetSdkVersion.

Remove the error message and instead erase the old setting if the
"repeatable" flag is not set.

https://github.com/MusicPlayerDaemon/MPD/issues/684

This code path is 2% faster.

10% speedup.  Strange, huh?

For some reason, this speeds up the library by 2%.