minor changes
this is a test
added skeletal code for expr_builder
..
started to add bop for different expr, also added some tests
unary ops
added a generic test method for integer binary operators
Merge branch 'master' into ido
moved __type to MExpr
checking push
merged
Merge branch 'ido' of github.com:aleksandarmilicevic/alloy_ruby into ido

Conflicts:
	lib/alloy/ast/expr_builder.rb
small changes
minor spacing
Merge branch 'ido' of https://github.com/aleksandarmilicevic/arby into ido
added skeletal code for computing types, and a simple example for computing the type for the PRODUCT operator
Merge branch 'ido' of github.com:aleksandarmilicevic/alloy_ruby into ido