Adding missing image to offline cache
Merge pull request #4 from darkwing/offline-capabilities

Adding offline capabilities now that simulator is 2.0
Copyedits, first pr to see if I'm doing it right.
Merge pull request #6 from markgif/master

copyedits. First test to see if I'm doing this right.
Copy edits. Adjust manifest code.
Merge pull request #7 from markgif/master

Copy edits. Adjust manifest code.
Update README.md: mozilla, not darkwing fork
Merge pull request #8 from krallja/patch-1

Update README.md: mozilla, not darkwing fork