allow a timer to have a start delay
issue#661 update state before values are cleared

this prevent loosing state values related to physics bodys
and inputs before `state.update` is called.
Small additions from the past week.
remove physics loader flags in p2 world, fix naming in loader
fixed p2 physics loading format and added the ability to extract a single fixture
PhysicsEditor expoerter updated. Added fixtureKey field. Changed id from lime-json to phaser-json. This ID is used by PhysicEditor to select the appropriate exporter. You have to select Phaser Exporter from the Dropdown list again when you update the exporter. No other breaking changes.
Renable input on Phaser.Image fix
Merge pull request #674 from georgiee/tidy-up-physics

PhysicExporter update, updated flags in Cache & Loader
If you inputEnable = false a gameobject you couldn't re-enable it again using inputEnable = true, only directly via the handler (thanks @nickrall, fix #673)
Updated the PhysicsEditor plugin to maintain position, radius, mask bits, category bits and sensor flags (thanks @georgiee, #674)
Merge pull request #663 from clark-stevenson/patch-2

Small additions from the past week.
Merge pull request #660 from georgiee/timer-start-delay2

Allow a timer to have a start delay
Timers can now have a start delay value (thanks @georgiee, #660)
Updated to Pixi 1.5.2 release.
Fixed Pixi UMD wrapper.
SoundManager.boot will check to see if the AudioContext was created before carrying on (thanks @keyle, fix #669)
Added Phaser.Point.centroid function.

Added static Phaser.Point.centroid function to calculate the centroid or midpoint of an array of points.
Updated Phaser.Point.centroid function.

Performance boosts and bugfix with averaging.
Update Point.js
Update Point.js
Added positionUp to Pointer