I installed a while ago geth 1.4.17 from the git repo (together with cpp-ethereum, the genoil CUDA miner, and the Mist GUI wallet). However, now I can't figure for the life of me how to upgrade geth to 1.5.x (in preparation for the impending hard-fork), so I just downloaded the latest version of Mist (0.8.7), and it's syncing to the blockchain just fine. How can I ensure that it will be running on the new, hard-forked chain, though?