Don't overwrite str object, fix BreakpointWindow (issue #43)
Don't overwrite str object, fix BreakpointWindow (issue #43)

A variable stupidly named `str` was being used, meaning that `str()`
couldn't be used to cast a number to a string. This has been changed,
fixing a problem with the breakpoint window opening.

Taluu/vdebug,sumyfly/vdebug,mispencer/vdebug,Taluu/vdebug,AndBicScadMedia/vdebug,benjifisher/vdebug,joonty/vdebug,sumyfly/vdebug,tjwallis/vim,Taluu/vdebug,paprykarz/vdebug,coffeine-009/vdebug,tjwallis/vim,mispencer/vdebug,AndBicScadMedia/vdebug,tjwallis/vim,jerray/vdebug,tjwallis/vim,benjifisher/vdebug,joonty/vdebug,jerray/vdebug,coffeine-009/vdebug,tjwallis/vim,paprykarz/vdebug,mispencer/vdebug,jerray/vdebug,coffeine-009/vdebug,AndBicScadMedia/vdebug,benjifisher/vdebug,joonty/vdebug,sumyfly/vdebug,paprykarz/vdebug