Annotate/CeylonEnter: reset annotations too for bootstrapping
BoxingDeclarationVisitor: more resilient to errors
Bootstrapping: generate fake AST for Ceylon trees rather than mock with symbols

That's all a lot saner
Bootstrapping: removed compile-time dependencies to language module
Naming: turned $impl into a constant and added a method to get an impl name
CeylonEnter: only reset class symbols from the language module

It should be a lot cleaner and try harder to figure out if we're compiling something or not
but ATM I can't figure it out and it works good enough for the language module
CeylonEnter: when bootstrapping call enter on all trees in one go
cosmetic: imports cleanup
CeylonModelLoader: change how we look classes up with postfix "_"

this was required to not load a bullshit ceylon.language.true class symbol that came out of
nowhere. hope it doesn't break anything else
JCTypeResetter: also reset annotations
MiscTest: added a few files that were missing for compiling the language module