[boost] [serialization][graph] Links to the getting started documentation

Hi, Both serialization and graph documentation contains links to sections of the old getting started documentation which was rewritten a while ago, so now they just end up at the getting started introduction. The attached patches try to change the links to somewhere more useful. In the graph documentation, I changed the 'Boost Jam Build Instructions' link to point to the instructions in boost build, as getting started doesn't seem to have a single location to point to. Is it okay to commit them (for trunk and release)? Daniel