2.0 Added more settings

A big thanks to @jamestruhlar for his PR, this is what he added :

• Added a new "Constraint" setting, which defines how the panel behaves relative to the player :
  • None : The panel stays where it got placed in world space.
  • Position : The panel sits in the player's playspace and moves with them.
  • View : The panel stays in front of the player's face like a HUD
• Added a new "Require Stopped" setting : If enabled, the panel can only be opened while the player isn't moving too fast. For instance, this can be useful in swimming worlds to prevent people from accidentally opening the panel while swimming.
• Each setting now has a tooltip explaining what each setting does
• API changes : New public methods to set the constraint mode

Additionally, I made those changes :

• The AndroidPanelModule now works on IOS also, but I didn't renamed the prefab to make the updating steps easier (no need to delete older prefabs,, importing the unitypackage is good enough)
• Fixed an issue of the "ThrowablePanel" prefab spinning after respawning when the closing behavior was set to "Respawn"
• Fixed an issue that prevented the panel from opening on newer Vive controllers.