Implement random Color generation
Update file
Add custom seed for random numbers
Add new options to random color generation
Tweak random color generation
Move SeededRandom into CesiumMath
Randomize alpha component
Add unit tests for random color generation
Fix picking in the CZML Sandcastle example

Fixes #1049
Resize extent for appearance rendering specs
Merge pull request #1055 from AnalyticalGraphicsInc/fix-sandcastle-czml-picking

Fix picking in the CZML Sandcastle example
Merge branch 'master' into random-color
Finish up random color generation.
Merge pull request #1058 from AnalyticalGraphicsInc/amdfixes

Test fixes for AMD
Copy fixes from ab257e79501628190a3f7853df88da647a5cbef2

Also use Color.fromRandom in this example.
Update LICENSE.md and CHANGES.md
Clean up license comments.
Add license comments, and comment out unneeded code.
Match Math.random by using the range [0, 1) instead.
Fix typos.