FIlters Added.. again!

some filters added to pixi
example 15 added too
updating Detector to use new ThreeJS method which supports more environments (like SublimeJS)
update Detector.js; now supports SlimerJS and other environments
Merge branch 'detector-fix' of https://github.com/mattdesl/pixi.js into detector-fix
Merge pull request #358 from mattdesl/detector-fix

Updating Detector.js to use latest check
attempt to get a 'webgl' context when 'experimental-webgl' fails
ie11 patch

Tempory patch to force canvas in ie11 until i get webGL working in there
merge dev-webgl-filters into dev
Canvas Tweaks
Canvas + removed
Displacment Map Added
fixed bug in masking example