[boost] Auto-linking and getting started docs.

I've added a section on auto-linking with MS-Windows compilers in the getting started docs, in the main branch only (No URL yet, cvs hasn't cycled it through yet, but it'll be at http://cvs.sourceforge.net/viewcvs.py/*checkout*/boost/boost/more/getting_st... eventually). If it looks OK, I'll commit to the release branch as well. John.