[WIP] New type inference

[gberaudo]

Switch to the new type inference version of the compiler.
See https://github.com/google/closure-compiler/wiki/Using-NTI-%28new-type-inference%29

There are only 2 errors left:

ERR! compile /home/gberaudo/dev/ol3/src/ol/observable.js:22: ERROR - ol.Observable cannot extend this type; structs can only extend structs
ERR! compile ol.Observable = function() {
ERR! compile                 ^
ERR! compile 
ERR! compile 
ERR! compile /home/gberaudo/dev/ol3/src/ol/renderer/maprenderer.js:38: ERROR - ol.renderer.Map cannot extend this type; structs can only extend structs
ERR! compile ol.renderer.Map = function(container, map) {
ERR! compile                   ^
ERR! compile 
ERR! compile 
ERR! compile 2 error(s), 0
ERR! compile  warning(s)
ERR! compile 
ERR! Process exited with non-zero status, see log for more detail: 2 

TODO:

• fix structs can only extend structs error;
• fix publish.js

[gberaudo]

@fredj, if you want to have a look...

[tschaub]

This looks like a mistake to me. There are still a number of places in the library that use the ol.events.Event.stopPropagation function. With this change, that will be undefined. I hope this causes at least a few test failures.

Not sure why you'd want it to be a prototype member. A name like ol.events.stopPropagation could make sense, but it doesn't need to be accessible from ol.events.Event instances.

[gberaudo]

The structs can only extend structs error seems to be gone after @tschaub's PR.
However there are lots of other errors, notably about nullable types.

[probins]

@gberaudo I notice a couple of typedef-related changes in here. First, LRUCache looks like it should be changed to an interface, so I won't include this in my typedef PR. Second, in raster/operation.js you're adding goog.require('ol.raster.Pixel') even though that is only used in comments/typedefs. Were you getting some sort of error here that prompted you to add the goog.require()?

[gberaudo]

@probins, thank you for caring about this PR.
I think it is better to ignore the changes here since some of them may be due to goog dependencies or the way the code is organized. Let's move the typedefs as discussed.