Minor maintenance release to address some issues introduced in 1.1.7:
- fix build against glib < 2.30 (#202)
- fix dsound audio driver on windows (#215)
- fix a bug around
synth.audio-groups setting, which caused improper multi-channel rendering (#225)
- cmake >= 3.0.2 is now required
- compilation with clang is now possible
- build fixes on OS/2 (thanks to @komh)
