add a 'centered' macro property that draws objects around their centers (fix #10)
refactor property handling. properties can now be retrieved by either using shape.get('propertyName') or shape.properties.propertyName. the old way of using shape.propertyName doesn't work anymore in order to avoid naiming conflicts. The only exception to this rule is the children object, which is still accessible via shape.children.
(fix #11)
add optional argument to Gmynd.setup specifying the container of the gmynd sketch
defaults to body.
make the conainer a jquery object
Merge branch 'master' of https://github.com/phlsa/gmynd