[IMP-dev] Logging

Logging is currently a bit of a mess in IMP as it basically output whatever I was last interested in looking at. One way of systematizing it would be VERBOSE: each restraint/state should output enough information to determine the flow through the code. For example, a restraint should print out each term of its energy (so the energy for each pair of particles for example). TERSE: each restraint/state should print a constant number of lines per evaluate call