Improved GLSL constructor expression test message

Improved the message for GLSL constructor expression tests by adding the
type expression to the message.
Notepad++ fixed some typos.

Fixed some types hinted by Notepad++.
sdk\tests\test-guidelines.md : Set the year in the licence text to 2014
Add a test for nested structs with same name.

This tests covers an ANGLE bug where nested structs are relabled
incorrectly, giving rise to compile and/or link errors.
Merge pull request #533 from jamiemadill/nested-structs

Add a test for nested structs with same name.
Merge pull request #532 from TiborsHub/master

Improved GLSL constructor expression test message
Conformance test for glsl array of structs with first pos int or bool.

At the time of writing, in Mac OS X with some NVIDIA cards, reading an array of
structs using a loop variable where the struct has an int or bool as its first
member returns corrupted data.

This adds a test with three examples:
- struct with unused int in first position
- struct with unused bool in first position
- struct with used bool in first position
Merge pull request #534 from jenanwise/array-of-struct-with-int-first-position

Conformance test for glsl array of structs with first pos int or bool.
Updated OES_half_float conformance test to ensure uint16 typed data is allowed
Renamed one function for clarity
Merge pull request #518 from toji/uint16_half_float

Updated OES_half_float conformance test to ensure uint16 typed data is allowed
Verify if component values are set correct

GLSL constructors : Added code to verify if component values are set
correct by constructor expression.
Fix a bug in oes-texture-float.html

If we read from a FBO without alpha, and the read format is RGBA,
alpha should be set to 1.
Merge pull request #546 from zhenyao/fix

Fix a bug in oes-texture-float.html
Added an indexed png with transparent pixels.

I thought there was a bug in the browsers but writing this test
I realize it was wrong. The browsers are already correct.

Whether you think this should be added or not is up to you
Added test for a Chrome regression that corrupted 2D canvas rendering after the canvas was used as a texImage2D source
Added reference to Chrome regression bug
Merge pull request #547 from greggman/add-indexed-png-test

Added an indexed png with transparent pixels.
More consistent use of canvas.width/height instead of hard coded numbers
Merge pull request #548 from toji/canvas_as_texture

Added test for a Chrome regression with canvas 2D
Only restore the context on preventDefault

preventDefault() appears to *set* the cancelled flag, so we should abort context restoration if the cancelled flag is *not* set.