- refactoring / cleanup of code generator:
 * added getOperationFormatedItemName method to reduce code duplication:
this is used for getting a string version of instance names
 * modified methods to match
 * updated boolean operations code generation to return new instances instead
of modifying old instances
 * overall minor cleanups
-first working draft of subtraction2
- added removal of renderables of operands for subtraction
- improved fallback order for getting item istance name
- partial cleanup of subtraction:
 * most of the code has now been moved to the shape3d class
 * updated api use and event dispatching to match
 * added import of Subtraction2 operation
- big refactoring of code-generator:
 * it is now a class with the previous "free floating" functions as methods
 * cleaned up structure accordingly
 * added object name formating methods : toTitleCase, uncapitalizeFirstLetter etc
so that no variables with spaces etc get created in the generated code
 * added newline insertion every time the target object changes:
this create better "logical blocks" in the generated code
 * added _lastTarget attribute to track last target to achieve the above
- modified editor to use updated api for code generation:
 * usco-editor now has a code-generator instance for ...code generation !
 * removed obsolte script import