New Visualizers for the Forces,

added a worldforce option to be based on the output node
Changed the direction of the force arrows to match the force direction
Added better looking icons
Updated Icon of the library
added a libraryinfo.mos so the library can be found in the library selection
Updated QuadraticSpeedDependantForce so that it works properly
updated the pictures of the copyright so that they can be found independant of the working directory
Merge pull request #13 from fvanderlinden/master

Forces visualizers and extra forces
 * added inner Modelica.Mechanics.MultiBody.World as required by Modelica.Mechanics.MultiBody.Visualizers.Advanced.Arrow and Modelica.Mechanics.MultiBody.Visualizers.Advanced.DoubleArrow
 * The state variable PlanarMechanics.Joints.Prismatic.s is of type Modelica.SIunits.Distance which means that the minimum length is zero. This is not suitable for simulation which negative elongations. See also [Mo#446](https://trac.modelica.org/Modelica/ticket/446) where there was the same problem.
 * Did some cosmetics.
Merge pull request #14 from tbeu/master

Issues with SI.Distance and MB.World
Use MSL 3.2.1

since there is no Modelica.Icons.TypesPackage in MSL 3.2
Fixed typo
Fixed typo
Fixed typo
Fixed typo
Added s.start and v.start to Initialization group

Thus it is consistent with Revolute
Move position of param animation

Make it consistent with Prismatic
Merge pull request #17 from tbeu/patch-2

Fixed typos
Merge pull request #18 from tbeu/patch-3

Added s.start and v.start to Initialization group
Merge pull request #19 from tbeu/patch-4

Move position of param animation
Fixed typo