CFGFast: make the progress bar optional. Add support for progress callback.
CFGFast: make the progress bar optional. Add support for progress callback.

chubbymaggie/angr,iamahuman/angr,f-prettyland/angr,iamahuman/angr,schieb/angr,iamahuman/angr,axt/angr,angr/angr,f-prettyland/angr,schieb/angr,tyb0807/angr,angr/angr,chubbymaggie/angr,tyb0807/angr,f-prettyland/angr,tyb0807/angr,angr/angr,schieb/angr,chubbymaggie/angr,axt/angr,axt/angr