Thoughts about dependencies

gistfile1.txt

All functionlities of krad are enabled by default

Some of them (GUI (station manager), xmms2, jack, wayland, x11, some codecs) can be disabled during
configuration

To disable, we use either "--without-FUNCTION" or "--disable-FUNCTION" (I don't care which :)

The build system will fail if a function has not been disabled but the dependency is missing 
(just like today). There shall be no automagic like "If dependency is found on the system, 
feature "xyz" will be silently enabled, otherwise it will be silently disabled"

Instead of having to install the dep, there's another option now: Disable the functionality

So there's no change in the current behavior: You run "./waf configure" w/o options: you get 
everything compiled in or an error if a dependency is missing

The user will be notified (entry in logfile) if a needed functionality was disabled at build-time

Example: "krad_radio sysname input something" w/o jack-support will print "Feature jack was 
disabled at build time. Please rebuild without disabling support for jack" (or s.th. like that)

the current options "--x11" and "--wayland" will have to be changed to "--without-x11" and 
"--without-wayland" and their logic inverted (they activate a default-disabled functionality)

My priority of things to be made optional (will be different to oneman's view ;):
- gtk+:3 DONE: https://github.com/krad-radio/krad_radio/pull/10
- the mentioned wayland/x11-thingy (the are optional now) DONE: https://github.com/krad-radio/krad_radio/pull/11
- xmms2
- jack
- codecs like opus, vorbis, theora, vp8, flac and such (though personally I wouldn't ever disable 
  one of these)