adding fake black texture tests for desktop computer
Use absolute, not relative canvas position when logging errors

checkCanvasRectColor used to log position relative to the corner of the
rectangle being checked. Logging absolute canvas position makes more
sense when analyzing errors, so switch to that in the new and 1.0.2
versions of the conformance suite.
fix some request from Ken Russell about the new test added.
change the bugzilla link directly showing the bug bug fix on Firefox.
Merge pull request #308 from gabadie/change-green-to-blue

adding fake black texture tests for desktop computer
Merge pull request #313 from NVIDIA/report-canvas-position

Use absolute, not relative canvas position when logging errors