More IE 11 fixes

Part of #1616.

Fixes `INVALID_OPERATION: getUniform (Occurs when Geometry is used: link)` and brings us down to four test failures in DC1 (IE dev channel).  The model tests below pass when ran alone.

![image](https://cloud.githubusercontent.com/assets/782098/3322128/a0f1d630-f743-11e3-827c-c5cdc01f47f6.png)

Will take another look on Friday.