support for preserving object stacking
Only use strokeWidth in object scaling when stroke is set.

Also only use half of the strokeWidth, this matters especially when the strokeWidth is large compared to the object size.
Merge branch 'master' into scaling-strokewidth-fix
README: note to include html5shiv for old IE
Merge pull request #1670 from zigotica/patch-1

README: note to include html5shiv for old IE
Update object.class.js

Fix opacity for groups.
Before it was working just in simple situation, now it should be ok both in path-group and in normal groups and nested groups.
Update circle.class.js

Add option to circle for start and end angle, to draw an ARC.
in radians, not in degree to avoid writing a setter and getter that does the conversion.
Internally is better radians i think.
Update circle.js

Added start and end Angle to tests.
Update circle.class.js

fixed typo.
Update circle.class.js

Code styles error fix
Update path.class.js
Update arc.js
Update canvas.js
Update canvas_static.js
Update path.js
Merge pull request #1675 from asturur/Add-parameter-to-circle-startAngle-,-endAngle

Add Start and End angle to circle.
Merge pull request #1672 from asturur/opacity-fix

Fix opacity for groups and nested groups
Fix issue with document fragments.
Update arc.js
Update arc.js

Fixed again code style