Build CFG immediately.
Add SSA transform.
SSA tweaks.
Add preliminary SSA DICM transformation (issue #7).
Add SSA optimize transformation.
Add AST normalizer.
Add local variable barrier refining.
Add a partial evaluation pass.
Use CFG block metadata.
Fix several minor bugs.
Merge remote-tracking branch 'origin/master' into dicm

Conflicts:
	lib/furnace-avm2/transform/ast_build.rb
Merge branch 'master' into dicm
Add IterativeProcess transform.
Add profiling support.
Implement phi node creation.
Use parallel gem to speed up processing on MRI.
Fix (phi nil) bug.
Add a new visualizer.
Fix a bug in PackageToken.
Avoid non-propagation of phantom stacks through redundant nodes.