Clear the screen before each batch

Makes processing warnings easier
* Fix problem found by closure: handle missing semantics
* Fix problem found by closure: type annotation
* Fix problem found by closure: extra element does not need to know the profile of the parent
Introduce _getAttributeAsFxLink
Fix problem found by closure: type annotations
Fix problem found by closure: type annotations
Fix problem found by closure: type annotation
Fix problem found by closure: missing member
Fix problem found by closure: attribute parsed with wrong type
Split code for <bind_vertex_input> and <bind> into separate methods
Fix problem found by closure: missing member
Fix problem found by closure: type annotation
Fix problem found by closure: type annotation
Make the logging function global

Disadvantage: All loader and file instances share the same log
Advantage: I do not need to pass the logger instance to each helper function and can replace several exceptions by log outputs
Replace some throws() by log output
Add remaining classes to the Collada namespace
Fix file name typo
Move link resolving functionality to the link classes
Move error reporting functions to the global namespace