merge #1510 from @sfentress

fix #1429; add some extra info to the progress event

Merge branch 'master' of https://github.com/GoodBoyDigital/pixi.js ...

Conflicts:
	bower.json
	package.json

-[HOUSEKEEPING] Some typo fixes.

-[LOADER] Json loader now loads spine files as per the new implementation.

Documentation - Array(Normalization) ...

YUIDoc does not have a standard (or really any) way of describing inner
types of arrays and there are two general forms used in the current pixi
code:

- `Array<X>`
- `Array An array of X`, or an _inconsistent_ variation of such

The first form is not even parsed correctly by the YUIDoc tool and the
contained type, X, does not appear in the documentation output (or parsed
data) at all. Other similar forms that fail to work are: `X[]`,
`Array{X}`m and `Array.<X>`.

The second form mixes the type (`Array`) and the description of the type
("An array of X"). It would suiting to say "Array of X".

Thus thus commit changes _both_ of the above forms into a normalized
`Array(X)`

While I do not want to impose this as the final chosen representation for
such types, it does _immediately_ address the documentation issues
mentioned above _and_ renders the nested type name in the documentation
output.

If a better method or converntion is found this _consistent_ and
generatable intermim VB-like syntax can be trivially found and replaced.

Another alternative of course, it to forbid anything more complex than
`Array` as a type.

JsonLoader should verify that the JSON data do include a meta.image property

Fixed SpineLoader jsdoc.

jsdoc fixes for all the Loader classes. SpriteSheetLoader is redundant and should be removed from the grunt tasks imho.

Merge pull request #964 from krzysztof-o/dev ...

fixes #619: correct size of trimmed sprites

merge in some doc fixes (#967)

doc addition

few small doc changes

fixes #619: correct size of trimmed sprites

fix some merge issues

update from dev

Merge pull request #851 from FedeOmoto/dev ...

When handling a restored webgl context event, save the newly created context and remove the lost one

Prefer bind over 'var scope = this;'

updating branch with latest dev

ImageLoader documentation fixes

Fix the ImageLoader.loadFramedSpriteSheet method to generate frames correctly

Refactored the JSON Loader slightly to cope with the new Texture trim / crop values.

be sure to mixin to json loader

update to latest dev

Fix #815, add webp support

Only use XDomainRequest in IE, if a crossorigin request is needed

Tweaked JSON Loader window.XDomainRequest

republished and linter code

Fixed Ajax bug for ie9 and ie10

Tidied up json loader ...

Set ajaxRequest to be asynchronous
Added an error even back in