Installing jshint and fixing errors

 - parsefloat does not take a radix
 - fixing spaces and tabs mixup (yell at Stemkoski)
 - Not declaring dozens of globals by fixing comas

Addresses issue #15
Fixed parseFloat and global issues
Removed gravity experiments. Updated examples to use new properties
Updated README. Grunted build
Removed old playground folder
Updated package version
`static` -> `isStatic`. Tabs -> spaces. Removed gravity playground.
Bumped version number to 0.7.0 and updated headers.
Merge branch 'dynamicAttributeUpdating' into dev

Conflicts:
	README.md
	build/ShaderParticles.js
	build/ShaderParticles.min.js
	examples/sphere.html
	package.json
	src/ShaderParticleEmitter.js
	src/ShaderParticleGroup.js
Fixed issue with dynamicAttribute example.
Fixing jshint errors again
Merge pull request #24 from DelvarWorld/linty

Fixing jshint errors again
Removed old uniforms from shader code. Removed pointless vec4 pos assignment in vertex shader.
Moved basic example back to using smokeparticle texture.
Adding jshintrc to root, whoops

This should have been in the original jshint PR. It defines the correct
globals so jshint doesn't yell at us when using THREE for example
Squashed sizeStart and sizeEnd, and opacityStart, opacityMiddle, opacityEnd into size and opacity attributes respectively.
Trying (and failing) to get mat3 attributes working.
Moved angle and angleAlignVelocity to a shared vec2 attribute named angle
Added sizeMiddle functionality
Updated dev build