expression visitor
Expression visitor knows literals
Pull from deboer.
expression visitor first pass, happy
Merge branch 'master' of github.com:jbdeboer/bridge
cleaned up ExpressionVisitorTest, ClassMemberVisitorTest
removed the obsolete bridge_visitor_test.* files
Merge branch 'master' of github.com:jbdeboer/bridge
Fixed the block_visitor (many thanks to deboer).