Internet Explorer compatibility fix and bugfix

* IE9-10 require explicit contexts to be passed to function pointers in certain cases (http://msdn.microsoft.com/en-us/library/ie/gg622930%28v=vs.85%29.aspx). The `process.nextTick` implementation used for IE, which is based on `setImmediate`, was updated to accept and pass an explicit context to the callback.
* The implementation for DataTable.Row did not declare `self` to be a local variable, and IE9 wouldn't allow a new value to be assigned to it.