title: Change gcc compiler executable name in BJam
body: <p>How to change compiler executable name? I want to perform a "fake build" of some products which are using BJam as build system. (For example: the Boost itself) In this "fake build" I want some special command to be called instead of g++. (with all the options and environment used in real build with real gcc).<br>
  How to perform this? Are there any command line switches which already allows me to do what I need or maybe I can somehow modify *.jam files to achieve what I need?</p>