Introducing Slicegroups

- contains 1 or more slices
- Array of Slices given at creation
Introducing Methods for Slicegroups

- Pie.groupSlices(firstsliceId,lastsliceId) creates a new slicegroup
with all the slices between and including firstsliceid and lastsliceid
- moveSLicegroup() moves a group of slices
- offsetSlicegroup() moves the slicegroup away from the center of the
pie
- remove methods
- methods for finding a slicegroup by the id of a slice in it
- documentaition will follow soon
Code Cleanup and incode Documentation

- bloated source with documentation of new methods and Objects
- refactoring and minor internal fixes

IMPORTANT:
- renamed Pie.wrapper() to Pie.html() for clarification
- renamed removeSlicegroup...() to ungroupSlicegroup...()
- renamed Slice.equal() to Slice.equals()