Änderungen

Summary

1. add real typecasting functions (details)
2. add map function (details)
3. move typecasting tests (details)
4. add forEach ext funcs for groups (details)

Commit 895785cb611b204ed1675a3c8508d2ab2dcddac2 by frotty add real typecasting functions
	wurst/_wurst/TypeCasting.wurst (diff)
Commit 04f6cca4d3586bb8a0d100961546fe0a4cadd1aa by frotty add map function
	wurst/data/LinkedList.wurst (diff)
Commit 9f7ad37526eb7f12bbf32a63fe6b5dc868bc2065 by frotty move typecasting tests
	wurst/_handles/primitives/StringTests.wurst (diff)
	wurst/_wurst/TypeCasting.wurst (diff)
	wurst/data/LinkedList.wurst (diff)
Commit a51cb3ef32151da68bf9711b1b63b39321ccbe79 by frotty add forEach ext funcs for groups
	wurst/closures/ClosureForGroups.wurst (diff)