Adds a bunch of music that fits really well into the RimWorld.
   
Music by LoboLoco (www.musikbrause.de, freemusicarchive.org):
  - Happy Hour,
  - Hometown Streetlife,
  - Jerry Gamblers Gang,
  - Jerry Gamblers Gang B,
  - Jerry Gamblers Harper,
  - Mountain Creek,
  - High Valley Hometown,
  - Crumpet River A
Licenced under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0

Music by Kevin MacLeod (incompetech.com):
  - Eastern Thought
  - Mystic Force
  - River Fire
  - Send for the Horses
Licensed under Creative Commons: By Attribution 3.0

Music by Purple Planet (purple-planet.com):
  - Rain On Lake Erie
  - The Big Sky
  - Tranquility
  - Uluru
  - Shifting Sands
Licensed under Creative Commons: By Attribution 3.0

Music by Shake That Little Foot (freemusicarchive.org):
  - Shady Groove
Licensed under Attribution-NonCommercial-ShareAlike 3.0 International License.

Music by Eino Toivanen (kongano.com):
  - Wilderness
Licenced under Creative Commons: By Attribution 4.0

Music by Entertainment for the Braindead (freemusicarchive.org):
  - Solitude
Licenced under Creative Commons: Attribution-NonCommercial-ShareAlike 3.0

Music by Jason Shaw (audionautix.com,freemusicarchive.org):
  - Back To The Woods
  - Namaste
Licenced under Creative Commons: Attribution 3.0 United States

Music by Simon Swerwer (soundcloud.com):
  - The Storm And The Bounty
Licenced under Creative Commons: Attribution-NonCommercial-ShareAlike