[boost] [build] Use address-model in library filenames

Please add the address-model (32 or 64) into the encoded name which describes a library, so that 32-bit and 64-bit libraries may reside in the same dir. I'd like to avoid a lengthy debate, and if no one wants to do it just provide me with working code for accomplishing it and I'll submit a pull request. -- Follow me on Github: https://github.com/vinniefalco