Adding ability to preconfigure Builder compilers

Hello dan, jon, eford, 

Please review the following commits I made in branch 'azulus-compiler'.

ed6142ee54b9a5baa41cf3835c19454f4cc46440 (2013-03-29 13:48:58 -0700)
Adding ability to preconfigure compilers so that auto-compiling works

R=dan
R=jon
R=eford