boot.js: updated Brikz, changed code accordingly
boot.js: updated Brikz, moved bootstrapping to __init__s
boot.js: two-phase smalltalk, fixing _st, DRY class addition

smalltalk is started in two phases:
 phase 1 allows loading but does not contain runtime
 phase 2 adds runtime, initializes and starts the system

 _st is early bound while loading, so it is hacked
 out of runtime, where it rightfully belongs

 class adding/wrapping is DRYed to allow multiple
 wrapClassName for same arguments to be harmless
boot.js: update Brikz