Workaround robot errors in FF23+. Still need to figure out how to deal with zoom level. Refs #17442.

(cherry picked from commit 23abc082d571cecce77d3957c405fd5399622b81)
(cherry picked from commit b5c1bd5dfccfc0ed6d7b5b75b8be0cb35faefc38)
Signed robot applet with a "Dojo Foundation" public key to make Java 7u40 happy. Fix accidental nondeterminism when testing on slower machines. Refs #17442.

(cherry picked from commit 9e1dc62201b7cd06f1c052bae663882003cd3957)
(cherry picked from commit e6490e5ad503b97e79992bbad72f9b3953430b65)