Fix shader compilation failure in IE11.

Fixes #2358

A function needed only in 2D mode was not being included in 3D.  Other
browsers were ok with this because the functions that called the missing
one were never called, but IE had a problem with it.
Reorder 1.5 items in CHANGES.md
Fixed typo in CHANGES.md
Merge pull request #2359 from AnalyticalGraphicsInc/ieCompileFailure

Fix shader compilation failure in IE11.
Merge master to show