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
Merge pull request #1675 from asturur/Add-parameter-to-circle-startAngle-,-endAngle

Add Start and End angle to circle.