fix: #441: copyrighted songs in nifty-examples?

Added a LICENSE.others file to the project root that lists each sound/
song resource in the Nifty repository together with the license the file
is licensed under.

LICENSE.others

@@ -0,0 +1,45 @@
+
+This file lists all sound files included in this repository together
+with the licenses these files are under.
+
+* Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0) - https://creativecommons.org/licenses/by-nc/3.0/
+
+  - ./nifty-examples/src/main/resources/defaultcontrols/sound/Loveshadow_-_Almost_Given_Up.ogg
+    "Almost Given Up" by Loveshadow
+
+  - nifty-examples-processing/data/sound/744__elmomo__MutantJewsArp.mp3
+  - nifty-examples/src/main/resources/sound/744__elmomo__MutantJewsArp.ogg
+    http://freesound.org/people/elmomo/sounds/744/
+
+  - nifty-examples/src/main/resources/tutorial/sound/echoed_-_L.O.R.D..ogg
+    http://ccmixter.org/files/echoed/23071
+
+* Creative Commons Attribution 3.0 Unported (CC BY 3.0) - https://creativecommons.org/licenses/by/3.0/
+
+  - nifty-examples-processing/data/sound/27257__kerri__eagle_feather_short.mp3
+  - nifty-examples/src/main/resources/sound/27257__kerri__eagle_feather_short.ogg
+    http://freesound.org/people/kerri/sounds/27257/
+
+  - nifty-examples-processing/data/sound/34556__Corsica_S__reverse_bass_blip_2.wav
+  - nifty-examples/src/main/resources/sound/34556__Corsica_S__reverse_bass_blip_2.wav
+    http://freesound.org/people/Corsica_S/sounds/34556/
+
+* Creative Commons Sampling Plus 1.0 - https://creativecommons.org/licenses/sampling+/1.0/
+
+  - nifty-examples-processing/data/sound/19546__tobi123__Gong_mf2.wav
+  - nifty-examples/src/main/resources/defaultcontrols/sound/19546__tobi123__Gong_mf2.wav
+  - nifty-examples/src/main/resources/sound/19546__tobi123__Gong_mf2.ogg
+    http://freesound.org/people/tobi123/sounds/19546/
+
+* Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported - https://creativecommons.org/licenses/by-nc-sa/3.0/
+
+  - nifty-examples/src/main/resources/sound/a.ogg
+  - nifty-examples-processing/data/sound/a.mp3
+    "The Four of Us Are Dying" from the NIN-Album "The Slip" - https://en.wikipedia.org/wiki/The_Slip_(album)
+
+* Made by void with sfxr http://drpetter.se/project_sfxr.html or recorded from a keyboard - public domain
+
+  - nifty-examples/src/main/resources/tutorial/sound/select.wav
+  - nifty-examples/src/main/resources/sound/select.wav
+  - nifty-examples-processing/data/sound/select.wav
+  - nifty-examples/src/main/resources/tutorial/sound/intro.ogg