Add position information to constructor definitions

* fixes typer error from previous commit
Add support for objects on template level
Add support for empty tuples
Add support for default init variables
Add support for singleton types
Add support for throw expressions
Improve sugsc.test (add comparison of AST)
Fix mkTemplate: add anyRef as parent when needed
Fix if (without else) expr

* has used EmptyTree for else part before, but should be
  Literal(Constant()) instead
Fix proc definition

* explicitly use scala.Unit instead of TypeTree() for DefDef tpt
Add support for new with anonymous classes
Use makeBlock for block handling
Comment on EmptyTree as rest in template topic
Optimize sugsc.test: No need to compile twice for AST
Add support for default parameters + calls